Webster's Revised Unabridged Dictionary · 1913

Knave

Knave (nāv) , noun

[Old English, boy, servant, knave, Anglo-Saxon cnafa boy, youth; compare Anglo-Saxon cnapa boy, youth, Dutch knaap, German knabe boy, knappe esquire, Icelandic knapi, Swedish knape esquire, knafvel knave.]

1.
A boy; especially, a boy servant. [Obsolete] — Wyclif. Chaucer
O murderous slumber, Lay'st thou thy leaden mace upon my boy That plays thee music? Gentle knave, good night. — Shakespeare
2.
Any male servant; a menial. [Obsolete] — Chaucer
He's but Fortune's knave, A minister of her will. — Shakespeare
3.
A tricky, deceitful fellow; a dishonest person; a rogue; a villain.
A pair of crafty knaves. — Shakespeare
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; as, the knave of hearts.
Collocations (1)
Knave child , a male child. [Obsolete] — Chaucer