(a) space that is completely empty of all matter orgas(es) 真空. (b) space in a container from which the air has been completely or partly pumped out （容器的）真空状态: create a perfect vacuum 形成完全的真空状态. 
(usu sing 通常作单数) (fig 比喻) situation or environment characterized by emptiness （情况或环境的）空洞状态: There has been a vacuum in his life since his wife died. 他妻子去世後他的生活很空虚. 
(infml 口) = vacuum cleaner. 
(idm 习语) in a `vacuum isolated from other people, facts, events, etc 与其他的人﹑ 事等脱离或隔绝: live, work, etc in a vacuum 在与外界隔绝的环境中生活﹑ 工作等.> vacuum v [I, Tn, Tn.p] ~ sth (out) (infml 口) clean (sth) with a vacuum cleaner 用真空吸尘器清扫（某物）: vacuum the stairs, carpet 用吸尘器清扫楼梯﹑ 地毯等 * vacuum (out) the car 用吸尘器打扫汽车.
# `vacuum cleaner electrical appliance that takes up dust, dirt, etc by suction 真空吸尘器.
`vacuum flask (also flask, US `vacuum bottle) containerwith a double wall that encloses a vacuum, used forkeeping the contents hot or cold 保温瓶. Cf 参看 Thermos.
`vacuum-packed adj (esp of perishable foods) sealed in a pack from which most of the air has been removed （尤指易腐败的食物）真空包装的.
`vacuum pump pump that creates a partial vacuum in a vessel 真空泵.
`vacuum tube (US) (Brit radio valve) sealed glass tube with an almost perfect vacuum to enable an electriccharge to pass through, formerly used in radios, televisions,etc 真空管; 电子管.