A boyfriend is a regular male companion in a romantic and or sexual relationship, although normally not in long-term committed (e.g. marital) relationships, where other titles (e.g. husband, partner) are more commonly used. A boyfriend can also be called an admirer, beau, fiancé, suitor and soul mate.

A guy friend is a male friend that is simply a friend and not a lover. The word guy friend is often used instead of the word boyfriend because using the word boyfriend suggests the relationship is romantic.

Partners in committed non-marital relationships are also sometimes described as a significant other or simply partner, especially if the individuals are cohabiting.

Boyfriend and partner mean different things to different people; the distinctions between the terms are subjective. How the term is used will ultimately be determined by personal preference.

A 2005 study of 115 people ages 21 to 35 who were either living with or had lived with a romantic partner notes that the lack of proper terms often leads to awkward situations, such as someone upset over not being introduced in social situations to avoid the question.

A girlfriend is term for a female partner one is romantically or sexually involved with. It can also refer to a female friend.

This term is often used loosely, and there is some debate over what exactly constitutes a girlfriend. Having a girl to agree to such an arrangement can feel like a milestone for young males, and is often seen as a sign of status, based on the perception of the girl amongst the male's peers.

Partners in committed non-marital relationships are also sometimes described as a significant other or simply partner, especially if the individuals are cohabiting.

Girlfriend and partner mean different things to different people; the distinctions between the terms are subjective. How the term is used will ultimately be determined by personal preference.

A 2005 study of 115 people ages 21 to 35 who were either living with or had lived with a romantic partner notes that the lack of proper terms often leads to awkward situations, such as someone upset over not being introduced in social situations to avoid the question..

A day is a unit of time, commonly defined as an interval equal to 24 hours. It also can mean that portion of the full day during which a location is illuminated by the light of the sun, also known as daytime. The period of time measured from local noon to the following local noon is called a solar day.

Several definitions of this universal human concept are used according to context, need and convenience. In 1967, the second was redefined in terms of the wavelength of light, and it became the SI base unit of time. The unit of measurement for time called "day", redefined in 1967 as 86,400 SI seconds and symbolized d, is not an SI unit, but it is accepted for use with SI. A civil day is usually also 86,400 seconds, plus or minus a possible leap second in Coordinated Universal Time UTC, and, in some locations, occasionally plus or minus an hour when changing from or to daylight saving time. The word day may also refer to a day of the week or to a calendar date, as in answer to the question "On which day?" Day also refers to the part of the day that is not night — also known as 'daytime'. The life patterns of humans and many other species are related to Earth's solar day and the cycle of day and night (see circadian rhythms).