As a Noun: 1. In spoken language, the study of the speech sounds used to make the words. In signed languages, the study of the handshapes, movements, locations, etc. used to make the signs. English = phonology. 2. The small units of sound that people make when they say words. For example, the word ‘cat’ is made up of three sounds—K-A-T. In signed language, the different parts of a sign, e.g., DRINK is made up of CUP-handshape, MOUTH-location, and TURN-WRIST-movement, all at the same time. English = phoneme.