Meaning of UNION in English

UNION

(n.) A device emblematic of union, used on a national flag or ensign, sometimes, as in the military standard of Great Britain, covering the whole field; sometimes, as in the flag of the United States, and the English naval and marine flag, occupying the upper inner corner, the rest of the flag being called the fly. Also, a flag having such a device; especially, the flag of Great Britain.

Webster's English dictionary.      Английский словарь Webster.