The term 'stiff bristles' can be described by two crossword solutions: SETAE (5 letters) and AWNS (4 letters). SETAE are small, stiff hairs found on the bodies of insects and other arthropods. They are used for sensing the environment and for locomotion. AWNS are stiff, sharp-pointed bristles found on the leaves and stems of some plants. They are used to protect the plant from herbivores and to help disperse its seeds.