SLIP v. 3 definitions
To depart, withdraw, enter, appear, intrude, or escape as if by sliding; to go or come in a quiet, furtive manner; as, some errors slipped into the work. Thus one tradesman slips away, To give his partner fairer play. Prior. Thrice the flitting shadow slipped away. Dryden.
SMOKE n.
The visible exhalation, vapor, or substance that escapes, or expelled, from a burning body, especially from burning vegetable matter, as wood, coal, peat, or the like.