PLural. 1a: a long sharp tooth: such as (1): one by which an animal’s prey is seized and held or torn (2): one of the long hollow or grooved and often erectile teeth of a venomous snake b: one of the chelicerae of a spider at the tip of which a poison gland opens 2: the root of a tooth or one of the processes or prongs into which a root divides 3: a projecting tooth or prong