Fruit pit is a term used to describe the hard, inedible outer layer of a fruit that contains the SEED. The crossword solutions for this term are STONE (5 letters), SEED (4 letters), and PYRENE (6 letters). STONE is a hard material composed of minerals, which is often used to describe the hard outer layer of a fruit pit. SEED is the small, reproductive part of a plant that can grow into a new plant. Pyrene is a type of hydrocarbon found in some fruit pits, such as those of apples and peaches.