WordNet

cause to sink; "The Japanese sank American ships in Pearl Harbor"
(technology) a process that acts to absorb or remove energy or a substance from a system; "the ocean is a sink for carbon dioxide"
plumbing fixture consisting of a water basin fixed to a wall or floor and having a drainpipe
fall or descend to a lower place or level; "He sank to his knees" (同)drop, drop down
pass into a specified state or condition; "He sank into nirvana" (同)pass, lapse
go under, "The raft sank and its occupants drowned" (同)settle, go_down, go under
descend into or as if into some soft substance or place; "He sank into bed"; "She subsided into the chair" (同)subside

PrepTutorEJDIC

(水平面下に)〈船・太陽などが〉『沈む』・(…に)『下降する』,落ちる《+『into』(『to』)+『名』》・『量』(『勢い』,『程度など』)『が減る』,弱まる,下がる・〈健康・士気・名声・地位などが〉悪化する,衰える,下がる・(…の状態に)次第に落ち込む,陥る《+『in』(『into』)+『名』(do『ing』)》・(…に)深く入る,しみ込む《+『in』(『into』)+『名』》・〈船など〉‘を'『沈める』・…‘の'水平面の高さを下げる,‘を'低くする・(…まで)…‘の'『量(勢い,程度)を減らす』,‘を'弱める《+『名』+『to』+『名』》・〈井戸・穴など〉‘を'掘る・(…に)…‘を'沈み込ませる《+『名』+『in』(『into』)+『名』》・(…に)〈資本・労力など〉‘を'投ずる《+『名』+『in』(『into』)+『名』》 / …‘を'隠す;…‘を'無視する・《話》《しばしば受動態で》…‘を'だめにする,滅ぼす;失う・(バスケットボールで)〈球〉‘を'バスケットに入れる・(ゴルフで)〈球〉‘を'ホールに入れる・(台所・洗濯場・洗面所などの)『流し』・《米》洗面器(washbasin, washbowl) ・下水溝,下水だめ