terrestrial dynamical time vs astronomy

terrestrial dynamical time and astronomy both are nouns.

Word	Noun	Adjective	Verb	Adverb
terrestrial dynamical time	Yes	No	No	No
astronomy	Yes	No	No	No

terrestrial dynamical time (noun)	astronomy (noun)
(astronomy) a measure of time defined by Earth's orbital motion; terrestrial time is mean solar time corrected for the irregularities of the Earth's motions	the branch of physics that studies celestial bodies and the universe as a whole