Meaning of UNION in English
( n. )
A joint or other connection uniting parts of machinery, or the like, as the elastic pipe of a tender connecting it with the feed pipe of a locomotive engine; especially, a pipe fitting for connecting pipes, or pipes and fittings, in such a way as to facilitate disconnection.
Webster's Revised Unabridged English Dictionary. Пересмотренный полный словарь английского языка Webster. 2012