quad

(noun) one of four children born at the same time from the same pregnancy. Synonyms: quadruplet.

(noun) a muscle of the thigh that extends the leg. Synonyms: quadriceps, quadriceps femoris, musculus quadriceps femoris.

(noun) (printing) a block of type without a raised letter; used for spacing between words or sentences. Synonyms: space.

(noun) a rectangular area surrounded on all sides by buildings. Synonyms: quadrangle.