a single thing or person.
any group of things or persons regarded as an entity: They formed a cohesive unit.
one of the individuals or groups that together constitute a whole; one of the parts or elements into which a whole may be divided or analyzed.
one of a number of things, organizations, etc., identical or equivalent in function or form: a rental unit; a unit of rolling stock.
any magnitude regarded as an independent whole; a single, indivisible entity.
Also called dimension. any specified amount of a quantity, as of length, volume, force, momentum, or time, by comparison with which any other quantity of the same kind is measured or estimated.