埋頭

to immerse oneself in / engrossed in sth / to lower the head (e.g. to avoid rain) / countersunk (of screws, rivets etc)

to bury

used in 埋怨[man2 yuan4]

head / hair style / the top / end / beginning or end / a stub / remnant / chief / boss / side / aspect / first / leading / classifier for pigs or livestock / CL:個|个[ge4]

suffix for nouns

to bury oneself in work (idiom); to be engrossed in work / to make an all-out effort / up to the neck in work