"tending to produce sleep," 1680s, from French soporifique (17c.), formed in French from Latin sopor (genitive soporis) "deep sleep" (see sopor). As a noun from 1722. Earlier as an adjective was soporiferous (1580s as "characterized by excessive sleep," c. 1600 as "soporific").
例文
1. the soporific effect of the sun
太陽の眠気覚まし作用
2.I dozed off during the soporific music.
眠りを誘う音楽を聞いて、いつの間にか居眠りをしてしまった。
3.The warmth of the room and the monotony of the speaker 's voice grew soporific .
部屋の熱気とスポークスマンの単調な声に眠気を催す。
4.After trudging for some distance,his slow steady steps acted as a soporific .