stifle v.

late 14c., "to choke, suffocate, drown," of uncertain origin, possibly an alteration of Old French estouffer "to stifle, smother" (Modern French étouffer), itself of uncertain etymology, perhaps from a Germanic source (compare Old High German stopfon "to plug up, stuff"). Metaphoric sense is from 1570s. Related: Stifled; stifling.