Dr. Johnson’s Dictionary

KNA’VISH. adj. [from knave.]
I. Dishonest; wicked; fraudulent.
‘Tis foolish to conceal it at all, and knavish to do it from
friends.  Pope’s Letters.
2. Waggish; mischievous.
Here she comes curst and sad;
Cupid is a knavish lad,
Thus to make poor females mad.  Shakesp.