middle watch vs midwatch

middle watch and midwatch both are nouns.

Word	Noun	Adjective	Verb	Adverb
middle watch	Yes	No	No	No
midwatch	Yes	No	No	No

As nouns, middle watch and midwatch are synonyms defined as:

middle watch and midwatch: a watch during the night (as from midnight to 8 a.m.)

Other synonyms of middle watch include graveyard watch, night watch.

middle watch (noun)	midwatch (noun)
a watch during the night (as from midnight to 8 a.m.)	a watch during the night (as from midnight to 8 a.m.)