Sly a. [Compar. Slier or Slyer; superl. Sliest or Slyest.]
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. [Obs.]
By the sly, or On the sly, in a sly or secret manner. [Colloq.] “Gazed on Hetty's charms by the sly.” --G. Eliot.
Sly goose Zool., the common sheldrake; -- so named from its craftiness.
Syn: -- Cunning; crafty; subtile; wily. See Cunning.