intelligence quotient, IQ, I.Q.

a measure of a person's intelligence as indicated by an intelligence test; the ratio of a person's mental age to their chronological age (multiplied by 100)

• adult intelligence — the average IQ of the adults in a given population
• borderline intelligence — the minimal IQ required for someone to function normally and independently in the world (without some form of institutional assistance)

• ratio — the relative magnitudes of two quantities (usually expressed as a quotient)