(music) meter with two subdivisions for every pulse

(botany) A fruit that develops from either a single or compound ovary within a flower with a single pistil.

(grammar) The perfective future tense.

plural of Simple Simon

A fool, or gullible person.

(mathematics, arithmetic) A fraction in which both the numerator and the denominator consist of whole numbers.

plural of simple engine

(group theory) A group which has no normal subgroups apart from the trivial group and itself.

An engine that has only a single stage, contrasting to a compound engine, compound locomotive, or triple expansion engine, which use multiple stages to improve efficiency.

plural of fee simple