muser vs ruminator

muser and ruminator both are nouns.

Word	Noun	Adjective	Verb	Adverb
muser	Yes	No	No	No
ruminator	Yes	No	No	No

As nouns, muser and ruminator are synonyms defined as:

muser and ruminator: a reflective thinker characterized by quiet contemplation

Other synonyms of muser include muller, ponderer.

muser (noun)	ruminator (noun)
a reflective thinker characterized by quiet contemplation	a reflective thinker characterized by quiet contemplation