とうか 投下 Common word LinksSentence search for 投下Sentence search for とうかKanji details for 投 and 下Edit in JMdict Noun, Suru verb, Transitive verb1. throwing down; dropping; airdrop1945ねん年広島にげんしばくだん原子爆弾がとうか投下された。An atomic bomb was dropped on Hiroshima in 1945.Noun, Suru verb, Transitive verb2. investment Discussions Log in to talk about this word.