To be seen through or to show through; either physically (e.g. clothing or paper being transparent) or metaphorically (someone's intention or feeling becomes apparent).
このブラウスは薄くて下着が透けて見える。
This blouse is thin and the underwear shows through.
彼の言い訳では本心は透けて見えるから、あまり信用できない。
His excuses reveal his true feelings, so they are not very trustworthy.
紙が薄すぎて裏の文字が透けて見える。
The paper is too thin and the text on the other side shows through.