Thrusty Clam Share definition Flag n. Insertion of the penis or a vibrator or dildo into a person's mouth such that speech is occluded, rendered incoherent or prevented altogether. Bitch starts chirping me, so I gave him the Thrusty Clam. Thrusty Clam by TOothFairy February 15, 2014 Get the Thrusty Clam mug.