1. 肛门：functional residual capacity 机能残气量 | fundament 肛门 | fundectomy 胃底部切除术

2. 基础,根本：→ fund 资金,基金;投资,资助 | → fundament 基础,根本 | → fundamental 基础的,基本的

3. 臀部/肛门/基础：fund-raising /筹募基金活动/ | fundament /臀部/肛门/基础/ | fundamentalism /正统派基督教/此派的运动/

noun

1. lowest support of a structure

e.g. it was built on a base of solid rock
he stood at the foot of the tower

Synonym: foundationbasefootgroundworksubstructureunderstructure

2. the fleshy part of the human body that you sit on

e.g. he deserves a good kick in the butt
are you going to sit on your fanny and do nothing?

Synonym: buttocksnatesarsebuttbacksidebumbunscanhindquartershind endkeisterposteriorpratrearrear endrumpsternseattailtail endtooshietushbottombehindderrierefannyass

3. the fundamental assumptions from which something is begun or developed or calculated or explained

e.g. the whole argument rested on a basis of conjecture

Synonym: basisbasefoundationgroundworkcornerstone