plural of REL

Initialism of Russo-European Laika.

(grammar) A pronoun that introduces a relative clause and refers to an antecedent. Some words that can be used as interrogative pronouns can alternatively be used as relative pronouns: what, which, who, and whom. The other relative pronouns are whoever, whomever, whatever, and that.

(grammar) A relative pronoun used in an adjectival clause.

(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.