Sly (?), a. [Compar.Slier (?) or Slyer; superl.Sliest or Slyest.] [OE. sli, slegh, sleih, Icel sl�gr, for sl�gr; akin to Sw. slug, Dan. slu, LG. slou, G. schlau; probably to E. slay, v.t.; cf. G. verschlagen sly. See Slay, v. t., and cf. Sleight.] 1. Dexterous in performing an action, so as to escape notice; nimble; skillful; cautious; shrewd; knowing; — in a good sense.
Be ye sly as serpents, and simple as doves. Wyclif (Matt. x. 16).
Whom graver age
And long experience hath made wise and sly. Fairfax.
2. Artfully cunning; secretly mischievous; wily.
For my sly wiles and subtle craftiness,
The litle of the kingdom I possess. Spenser.
3. Done with, and marked by, artful and dexterous secrecy; subtle; as, a sly trick.
Envy works in a sly and imperceptible manner. I. Watts.
4. Light or delicate; slight; thin.
By the sly, orOn the sly, in a sly or secret manner. “Gazed on Hetty's charms by the sly.” G. Eliot. — Sly goose(Zoöl.), the common sheldrake; — so named from its craftiness.
Syn. — Cunning; crafty; subtile; wily. See Cunning.