その反面[sonohanmen] on the other hand
に反して[nihanshite] against
違反者[ihansha] violator (of a law)
違反[ihan] violation (of law)
一律減反[ichiritsugentan] reduction in area of rice under cultivation

陰性反応[inseihannou] negative reaction (in patient)
化学反応[kagakuhannou] chemical reaction
可逆反応[kagyakuhannou] reversible reaction
核反応[kakuhannou] nuclear reaction
核反応炉[kakuhannouro] nuclear reactor

哀歌[aika] lament (song)
愛唱歌[aishouka] (one's) favourite song
詠歌[eika] poem (esp. tanka)
艶歌[enka] enka
応援歌[ouenka] rooters' song

歌い合う[utaiau] to sing responsively
歌い上げる[utaiageru] to sing at the top of one's voice
歌詠み[utayomi] tanka composer
歌会[utakai] poetry party or competition