Marduk vs Merodach

Marduk and Merodach both are nouns.

Word	Noun	Adjective	Verb	Adverb
Marduk	Yes	No	No	No
Merodach	Yes	No	No	No

As nouns, Marduk and Merodach are synonyms defined as:

Marduk and Merodach: the chief Babylonian god; his consort was Sarpanitu

Other synonyms of Marduk include Baal Merodach, Bel-Merodach.

Marduk (noun)	Merodach (noun)
the chief Babylonian god; his consort was Sarpanitu	the chief Babylonian god; his consort was Sarpanitu