peanut butter(n = noun.food) - a spread made from ground peanuts;
is a kind of paste, spread

   A paste made by mixing ground fresh roasted peanuts with a small quantity of water or oil, and used chiefly as a relish on sandwiches, etc. [Webster 1913 Suppl.]

anchovy butter, apple butter, bercy butter, bread and butter, bread and butter pickle, brown butter, butter, butter and eggs, butter bean, butter churn, butter cookie, butter daisy, butter dish, butter knife, butter up, clarified butter, cocoa butter, colbert butter, drawn butter, garlic butter, hog peanut, lemon butter, lobster butter, meuniere butter, nut butter, onion butter, peanut, peanut bar, peanut brittle, peanut gallery, peanut oil, peanut vine, peanut worm, pimento butter, shrimp butter, snail butter, wild peanut, witches' butter, yak butter