noun
very dim light; faint darkness
Describes a state of very weak light, often at dusk or in a dark room, where shapes are barely visible.
薄闇の中で、彼の顔はよく見えなかった。
In the very dim light, I couldn't see his face well.
夕方の薄闇が部屋を包んだ。
The faint darkness of evening filled the room.
Compound of 薄 (usu, 'thin, faint') and 闇 (yami, 'darkness'). The reading うすやみ follows standard rendaku for 闇.