埋首

máishǒu
to immerse oneself in (one's work, studies etc)

CEDICT

to immerse oneself in (work, study, etc.)

Wiktionary

努力做事。如：「只有埋首用功的人，才能金榜題名。」也作「埋頭」。

重編國語辭典

Entry Composition

1 埋 mái to bury
2 首 shǒu
  1. head
  2. chief
  3. first (occasion, thing etc)
  4. classifier for poems, songs etc

Related entries

埋頭 máitóu
  1. to immerse oneself in
  2. engrossed in sth
  3. to lower the head (e.g. to avoid rain)
  4. countersunk (of screws, rivets etc)
他整天都在埋頭埋腦地看小說，連飯也沒有吃。

He has been absorbed in the novel all day without eating.

Source: Tatoeba

沉潛 chénqián
  1. to lurk under water
  2. to immerse oneself in (study etc)
  3. to lie low; to keep a low profile
  4. quiet; reserved; self-possessed