どん底[donzoko] very bottom
井底[seitei] well bottom
海底[kaitei] bottom of the ocean
海底ケーブル[kaiteikeeburu] undersea cable
丸底[maruzoko] round-bottom

基底[kitei] base
靴底[kutsuzoko] shoe sole
黒底翳[kurosokohi] black cataract
根底[kontei] root
周知徹底[shuuchitettei] (something) known to all

辣油[raayu] Chinese red chile oil (chile, chilli)
あまに油[amaniyu] linseed oil
荏胡麻油[egomayu] egoma seed oil
英国石油[eikokusekiyu] British Petroleum
乾性油[kanseiyu] drying oil

肝油[kanyu] fish-liver oil (cod, shark, etc.)
含油層[ganyusou] oil strata
揮発油[kihatsuyu] gasoline
給油[kyuuyu] supply of oil
桐油[touyu] tung oil

鯥五郎[mutsugorou] mudskipper (Boleophthalmus pectinirostris)
川鯥[kawamutsu] dark chub (Nipponocypris temminckii)
赤鯥[akamutsu] blackthroat seaperch (Doederleinia berycoides)

油底鯥[aburasokomutsu] escolar (Lepidocybium flavobrunneum)
沼鯥[numamutsu] Nipponocypris sieboldii (species of cyprinid)
薔薇鯥[baramutsu] oilfish (Ruvettus pretiosus)