劍橋詞典to release or open something that is fixed or closed 解開(kāi)；松開(kāi)；打開(kāi) I can't unfasten this button /belt . 我解不開(kāi)這個(gè)釦子／帶子。 This blouse unfastens (= can be unfastened) at the back. 這件上衣是從背後解釦的。 返回 unfasten