universal time vs UT1

universal time and UT1 both are nouns.

Word	Noun	Adjective	Verb	Adverb
universal time	Yes	No	No	No
UT1	Yes	No	No	No

As nouns, universal time and UT1 are synonyms defined as:

universal time and UT1: the local time at the 0 meridian passing through Greenwich, England; it is the same everywhere

Other synonyms of universal time include GMT, Greenwich Mean Time, Greenwich Time, UT.

universal time (noun)	UT1 (noun)
the local time at the 0 meridian passing through Greenwich, England; it is the same everywhere	the local time at the 0 meridian passing through Greenwich, England; it is the same everywhere