俯きがち[utsumukigachi] looking down
俯向く[utsumuku] to hang one's head in shame
俯角[fukaku] depression
俯仰[fugyou] looking up and down
俯仰角[fugyoukaku] angle of elevation

俯向き[utsumuki] lying face down
俯向け[utsumuke] lying face down
俯向ける[utsumukeru] to turn upside down
俯伏[fufuku] prostration
俯伏す[utsubusu] to lie face down (e.g. on the ground, napping on a desk)