trivial vs fiddling

trivial and fiddling both are adjectives.

Word	Noun	Adjective	Verb	Adverb
trivial	No	Yes	No	No
fiddling	No	Yes	No	No

As adjectives, trivial and fiddling are synonyms defined as:

Other synonyms of trivial include footling, lilliputian, little, niggling, petty, picayune, piddling, piffling.

trivial (adjective)	fiddling (adjective)
concerned with trivialities	(informal) small and of little importance
of little substance or significance
(informal) small and of little importance