《c1390》 observe(n) (O)F observer L observre to watch, observe ← OB-＋serv🔗⭐🔉

《c1390》 observe(n) (O)F observer L observre to watch, observe ← OB-＋servre to heed, watch (← IE ser- to protect: cf. conserve) ob・serv・er /bzv ｜ -zv^（ｒ/

研究社新英和大辞典 ページ 208501 での【nO】単語。