Word

背伸び

背延び、背のび
せのび
standing on tiptoe and stretching one's back to make oneself taller; stretching oneself; overreaching oneself; overstretching oneself; trying to do something beyond one's ability; pushing to the limit
Word

背戸

せど
back door or entrance
Word

背教者

はいきょうしゃ
apostate; renegade
Word

背後関係

はいごかんけい
background (of an episode)
Word

背黒鰺刺

せぐろあじさし
sooty tern
Word

背黒ジャッカル

せぐろジャッカル
black-backed jackal (carnivore, Canis mesomelas)
Word

どんぐりの背比べ

団栗の背比べ
exp
どんぐりのせいくらべ
having no outstanding characteristics; to all seem about the same; bragging competition ("pissing contest") concerning matters of little importance; height comparison among acorns
Word

背日性

はいじつせい
negative heliotropism
Word

背中を出す

せなかをだす
to bare one's back
Word

峰打ち

刀背打ち
みねうち
striking with the back of the sword