An offering given to the priest at Whitsuntide, according to the number of chimneys in his parish.
“The Bishop of Elie hath out of everie parish in Cambridgeshire a certain tribute called ... smoke-farthings, which the churchwardens do levie according to the number of chimneys that be in a parish” —MSS. Baker, xxxix. 326.
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894