Look up guide in Wiktionary, the free dictionary.

Austrian mountain guides Anselm Klotz (left) and Josef Frey (right), 19th century

A guide is a person who leads anyone through unknown or unmapped country. This includes a guide of the real world (such as someone who conducts travellers and tourists through a place of interest), as well as a person who leads someone to more abstract places (such as to knowledge or wisdom).

Guide - meanings related to travel and recreational pursuits[link]

There are many variants of guides in this context, and guides are often employed in any aspect of travel or adventure, or wherever there is an advantage to the client in terms of knowledge provided in improving the overall travel experience or making the client feel more safe due to the presumed expertise of the guide.
These days guides will normally possess an area and field-specific qualification usually issued and/or recognised by the appropriate Guide's Association or licensing authority. However this is not always the case, and it is advisable for travellers paying a premium to go on an organised tour or journey because they think this will mean they will have a better experience to check the guide's qualifications beforehand.
Explorers in the past venturing into territory unknown by their own people invariably hired guides. American West explorers Lewis and Clark hired a Shoshone Indian woman Sacagawea, and Wilfred Thesiger hired guides in the deserts that he ventured into, such as Kuri on his journey to the Tibesti Mountains in 1938.
Aside from knowing the way or the area geographically, modern guides are usually hired to act as interpreters for those travellers who do not speak the local language and provide cultural, historical or other information on the area visited. Travel companies organising tours of large groups often have a guide or tour leader accompany the group. They might also be trained in First Aid and have other skills that reduce the risk for the tour operator to conduct these tours or the travel agency selling them.
Here are some examples of guide professions:

Tourist guide[link]

A tour guide at the Centre Block in Canada.

Tourist Guides are representatives of the cities, regions and countries for which they are qualified. It depends largely on them if visitors feel welcome, want to stay longer or decide to come back. They therefore contribute considerably to the perception of the destination. Tourist Guides are able to help travellers understand the culture of the region visited and the way of life of its inhabitants. They have a particular role on the one hand to promote the cultural and natural heritage whilst on the other hand to help ensure its sustainability by making visitors aware of its importance and vulnerability. [EN 13809:2003]

Mountain guide[link]

Mountain guides are those employed in mountaineering; these are not merely to show the way but stand in the position of professional climbers with an expert knowledge of rock and snowcraft, which they impart to the amateur, at the same time assuring the safety of the climbing party. This professional class of guides arose in the middle of the 19th century when Alpine climbing became recognized as a sport.

In Switzerland, the central committee of the Swiss Alpine Club issues a guides’ tariff which fixes the charges for guides and porters; there are three sections, for the Valais and Vaudois Alps, for the Bernese Oberland, and for central and eastern Switzerland.

In Chamonix (France) a statue has been raised to Jacques Balmat, who was the first to climb Mont Blanc in 1786. Other notable European guides are Auguste Balmat, Michel Cros, Maquignay, J. A. Carrel, who accompanied Edward Whymper to the Andes, the brothers Lauener, Christian Almer and Jakob and Melchior Anderegg.

Adirondack guides (carrying and rowing guideboats on the Raquette River, 1888

Wilderness guide[link]

A wilderness guide is a person who takes a number of individuals to visit some part of wilderness, such as forest, bogs, hills, on or off marked paths, and ensure the safety of the group while leading them through the wilderness which the guide has knowledge of.

The first priority is the safety of the group, which is why wilderness guides are expected to have a command of basic survival skills (such as making shelters, fire-making, hiking, orienteering and first-aid) as well as experience in survival in extreme conditions and all seasons, and how to deal with an emergency. The guide is also expected to have a deep understanding of the nature of the place he is guiding in, and able to answer questions of the group concerning the local flora and fauna, ecology, geological morphology, as well as cultural history of the place visited.

Other skills may include traditional handicrafts and cooking methods, fishing, hunting, bird watching, nature conservation and animal specialties.

These wilderness guided tours usually take place on foot (or skis or snowshoes if there is snow) but may also involve other vehicles such as cars, snowmobiles, canoes/kayaks, or sledges (traditionally pulled by huskies or reindeers in countries such as Sweden, Finland and Canada).^[1]

Hunting guide[link]

Guides employed by those seeking to hunt wildlife, especially big game animals in the wild. Hunting guides have been important in many areas of the world, including the American west, the Adirondacks, and Africa, etc. Hunting guides in Africa of European descent are commonly referred to as White hunter, although this is becoming a less fashionable term these days, as in most African countries today there are also native African "hunters" or hunting guides.

Safari guide[link]

Guides employed on safari, usually for "photographic safaris", although the term can also refer to a "hunting guide" or Professional Hunter. Safari guides who are self-employed, working on their own account with their own marketing and clientele (in contrast with those who work for an employer) sometimes refer to themselves as "professional safari guides".

Military guides and development of Guides Regiments[link]

In European wars up to the time of the French Revolution, the absence of large-scale detailed maps made local guides almost essential to the direction of military operations. In the 18th century the stricter organization of military resources led in various countries to the special training of guide officers who had the primary duty of finding, and if necessary establishing, routes across country. In the history of the American west, Native Americans and mountain men were important in leading military units and settlers alike.

The genesis of the "Guides" regiments may be found in a short-lived Corps of Guides formed by Napoleon in Italy in 1796, which appears to have been a personal escort or body guard composed of men who knew the country. Following the unification of Italy in 1870-71, the new national army included a regiment designated as Guides - the 19th Cavalleggieri (Light Horse).

In the Belgian Army the two Guides regiments, created respectively in 1833 and 1874, constituted part of the light cavalry and came to correspond to the Guard cavalry of other nations. Until the outbreak of World War I, they wore a distinctive uniform comprising a plumed busby, green dolman braided in yellow, and crimson breeches. Mechanised in October 1937, both regiments form armoured battalions in the modern Belgian Army.

In the Swiss army prior to 1914 the squadrons of "Guides" acted as divisional cavalry. In this role these light cavalry units were called upon, on occasion, to lead columns.

The "Queen’s own Corps of Guides" of the British Indian Army consisted of a unique combination of infantry companies and cavalry squadrons. After World War I the infantry element was incorporated in the 12th Frontier Force Regiment and the Guides Cavalry formed a separate regiment - the 10th Queen Victoria's Own Corps of Guides Cavalry (Frontier Force).

In drill, a "guide" is an officer or non-commissioned officer who regulates the direction and pace of movements.

Guide - metaphysical meanings[link]

Trip sitter[link]

A psychedelic guide is someone who guides a drug user's experiences as opposed to a sitter who merely remains present, ready to discourage bad trips and handle emergencies but not otherwise getting involved. Guides are more common amongst spiritual users of entheogens. Psychedelic guides were strongly encouraged by Timothy Leary and the other authors of The Psychedelic Experience: A Guide Based on the Tibetan Book of the Dead. Trip sitters are also mentioned in the Responsible Drug User's Oath.

Guided meditation[link]

Jim Bridger served as guide and army scout during the first Powder River Expedition against the Sioux and Cheyenne

In Islam[link]

In Islam "Ar-Rashid", one of the 99 Names of Allah, means The Guide. From this is derived the common Arabic name Rashid.

References[link]

 This article incorporates text from a publication now in the public domain: Chisholm, Hugh, ed. (1911). Encyclopædia Britannica (11th ed.). Cambridge University Press.  Original text from the 1911 Encyclopædia Britannica.

1. ^ Tampere College. "International Wilderness Guide program". http://www.tao.tampere.fi/tao/TAOWWWAIKUISET/era-_ja_luonto-oppaan_at_%28international_wilderness_guide%29.html. Retrieved 2011-10-13.