1. A boy; especially, a boy servant. O murderous slumber, Lay’st thou thy leaden mace upon my boy That plays thee music ? Gentle knave, good night. (Shak)
2. Any male servant; a menial. He’s but Fortune’s knave, a minister of her will. (Shak)
3. A tricky, deceitful fellow; a dishonest person; a rogue; a villain. A pair of crafty knaves. In defiance of demonstration, knaves will continue to proselyte fools. (Ames)
How many serving lads must have been unfaithful and dishonest before knave -which meant at first no more than boy acquired the meaning which it has now !
4. A playing card marked with the figure of a servant or soldier; a jack. Knave child, a male child.
Synonym: villain, cheat, rascal, rogue, scoundrel, miscreant.
Origin: oe, boy, servant, knave, as. Cnafa boy, youth; cf. As. Cnapa boy, youth, D. Knap, g. Knabe boy, knappe esquire, Icel. Knapi, Sw. Knape esquire, knafvel knave.