1. a figure of speech in which not the literal word but one associated with it is used, as the sword for war. Synecdoche is the form of metonymy in which a whole is represented by a part or vice versa, as in referring to a laborer as a hand or a police officer as the police.

2. in speech pathology, a disturbance in which imprecise or inappropriate words and expressions are used. —metonymic adj.