プログレッシブ和英中辞典(第4版)の解説
うっすら
slightly; faintly
庭には雪がうっすらと積もっていた
The garden was covered with a thin coat [layer] of snow.
うっすらと東の空が白み始めた
The eastern sky began to show faint signs of light.
少女はうっすらと化粧をしていた
The girl was lightly made up.
彼女はうっすらとほおを赤らめた
She blushed faintly.
彼女はうっすらと目を開けた
She opened her eyes slightly [partway].