- In a sly manner, cunningly.
- 1749, Henry Fielding, “In which Mrs. Miller Pays a Visit to Sophia”, in The History of Tom Jones, a Foundling. In Six Volumes, volume VI, London: Printed by A[ndrew] Millar, […], OCLC 928184292 ↗, book XVII, page 134 ↗:
- When ſhe was dreſt, therefore, down ſhe went, reſolved to encounter all the Horrours of the Day, and a moſt diſagreeable one it proved; for Lady Bellaſton took every opportunity very civilly and ſlily to inſult her; [...]
- 1851 November 13, Herman Melville, “The Town-Ho’s Story (As Told at the Golden Inn.)”, in Moby-Dick; or, The Whale, 1st American edition, New York, N.Y.: Harper & Brothers; London: Richard Bentley, OCLC 57395299 ↗, page 274 ↗:
- So when they were working that evening at the pumps, there was on this head no small gamesomeness slily going on among them, as they stood with their feet continually overflowed by the rippling clear water; [...]
- 1899, Knut Hamsun, “Part II”, in George Egerton [pseudonym; Mary Chavelita Dunne Bright], transl., Hunger: Translated from the Norwegian, London: Leonard Smithers and Co. […], OCLC 560168646 ↗; republished New York, N.Y.: Alfred A. Knopf, October 1920 (December 1920 printing), OCLC 189563 ↗, page 88 ↗:
- I lie there on the stretcher-bed and laugh slily, but say nothing; give vent to no opinion one way or the other.
- French: sournoisement
- German: verschmitzt, schlau
- Italian: astutamente, furtivamente
- Portuguese: maliciosamente
- Spanish: astutamente, arteramente