verb · to cover up or conceal

他用手掩住嘴巴，不敢笑出声来。

verb · to get one's fingers or body parts caught when closing a door or lid

小心别让抽屉掩了手。

verb · to launch a surprise attack or ambush (literary)

乘其不备，掩其不意。

verb · to close or shut a door, book, or similar object

离开时请随手把门掩上。