noun
Usage: usually capitalized 1st H
Etymology: h (II) (abbreviation for hour )
: the hour set for launching a specific tactical operation — compare d day , zero hour
noun
Usage: usually capitalized 1st H
Etymology: h (II) (abbreviation for hour )
: the hour set for launching a specific tactical operation — compare d day , zero hour
Webster's New International English Dictionary. Новый международный словарь английского языка Webster. 2012