seal /si:l/ I. n. ［c］ 1.封铅，封条：the required official seal 必需的官方封印；break/take off the seal 启封，折封 2.印，图章： the Seal of State 国玺 ‖II. vt. (密)封：seal an envelope 封信；seal (up) a tin 密封罐头 seal off 隔断，封锁：Police immediately sealed off the streets around the hotel as they searched for the bomb. 搜查炸弹时，警察立即隔断旅馆附近街道的交通。