I saw a curious phrase used in John Clay’s fine biography R. D. Laing: A Divided Self (Hodder & Stoughton, 1996). Laing and colleagues were looking for new premises for their experimental psychotherapy, and Kingsley Hall in London’s East End was a possibility. (It would become “a hallowed shrine of the counter-culture movement”.) Clay writes:
Sid Briskin visited and reported back favourably. Then he and Laing, both dressed soberly, went to visit the trustee of the building, Sidney Russell, Laing mentioning his working-class Glasgow background to provide credibility. Russell was convinced and offered them a five-year lease at a peppercorn rent.
Peppercorn refers to the dried berry of the pepper plant, and the word later became generalised, or semantically broadened, to also mean “a small or insignificant thing” (AHD4), “something trifling” (Collins), “anything very small or insignificant” (Random House), etc.
Peppercorn rent is a phrase in its own right, dating back several centuries, meaning a very low, nominal or token rent given as “a simple acknowledgement that the tenement virtually belongs to the person to whom the peppercorn is given”, as Brewer’s Dictionary of Phrase and Fable has it. But this negligible financial exchange was once quite literally pepper-based.
Oxford Dictionaries labels the phrase British and say it originates in a once-common practice of “stipulating the payment of a peppercorn as a nominal rent”. Merriam-Webster has similar information: (1) “a rent formerly often stipulated in deeds and consisting in supplying a certain amount (as a pound) of black peppercorns at stated intervals”; (2) “a merely nominal rent in kind operating to keep alive a title.”
There’s a little more history on peppercorn rent (and rose rent!) in Curious English Words and Phrases, and some legal notes at Wikipedia. Before reading the book on Laing, I don’t think I’d ever noticed it before. Are you familiar with the phrase, or have you ever paid a peppercorn rent?