astronomy vs terrestrial dynamical time

astronomy and terrestrial dynamical time both are nouns.

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

astronomy (noun)	terrestrial dynamical time (noun)
the branch of physics that studies celestial bodies and the universe as a whole	(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