noun
Usage: usually capitalized M
: either of a pair of hemispherical cups forming when placed together a cavity from which the air can be withdrawn by an air pump and used to illustrate the pressure of air
noun
Usage: usually capitalized M
: either of a pair of hemispherical cups forming when placed together a cavity from which the air can be withdrawn by an air pump and used to illustrate the pressure of air
Webster's New International English Dictionary. Новый международный словарь английского языка Webster. 2012