Of goods or merchandise, to be acquired by illegal or dubious means; to come into (someone's) possession without being paid for. Primarily heard in UK. Danny says he has several laptops and smartphones he wants to sell for cheap—sounds like they fell off the back of a lorry to me.
(British humorous) alsooff the back of a truck (Australian humorous)
if you say that you got something off the back of a lorry, you mean that it was probably stolen I don't know where he gets this stuff - probably off the back of a lorry.There's a new stereo too which, I suspect, fell off the back of a lorry.