peanut

Concise Oxford English Dictionary © 2008 Oxford University Press:
peanut/ˈpiːnʌt/

▶noun

• 1 the oval seed of a South American plant, eaten as a snack or used for making oil or animal feed.

• 2 the leguminous plant that bears peanuts, which develop in underground pods. [Arachis hypogaea.]

• 3 (peanuts) informal a paltry sum of money.

• 4 (peanuts) small pieces of styrofoam used as packing material.