A polite term for steal. Thieves are, by a similar euphemism, called conveyers. (Latin, con-veho, to carry away.)
“Convey, the wise it call. Steal! foh! a fico for the phrase.”— Shakespeare: Merry Wives of Windsor, i. 3.
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894
More on Convey from Infoplease: