fell off the back of a lorry

The phrase "fell off the back of a lorry" is a British slang term that means obtaining or acquiring something that is believed to be stolen, smuggled, or acquired through illegal means. It is often used humorously to describe a suspicious or dubious source of goods. The phrase implies that the item in question was possibly obtained through dishonest methods and was either accidentally or purposely dropped from the back of a delivery truck (lorry).