ｈｏｒ.ｓｏｍ.

(L) hora somni; or "at bedtime"; [Med:Lit].

就寝時に.
(Ｌ) ｈｏｒａ ｓｏｍｎｉ; ｏｒ "ａｔ ｂｅｄｔｉｍｅ";
[Ｍｅｄ:Ｌｉｔ].

丸善 「略語大辞典」 JLogosID : 11877112