(meteorology) The ratio of the actual amount of water vapor (absolute humidity) present in the air to the saturation point at the same temperature, usually expressed as a percentage.

(sciences) A measure of the density of a material. The ratio of the density of a substance to the density of water at the same temperature. It is dimensionless and therefore has no units.

(grammar) A subordinate clause that modifies a noun.

(grammar) the superlative (a degree of comparison) when it is used to express the highest degree of something in relation to something else

(set theory, of set A "in" set B) The set containing exactly those elements belonging to B but not to A.

A person who is related to another through a common ancestor, and not merely by marriage or adoption.

plural of blood relative

(mathematics, of two or more numbers) having no factors (except the number 1) in common.

(uncountable) A method of determining the age of a fossil by comparing its placement with that of fossils in other layers of rock. / (countable) An act of so doing.

plural of relative density