gearing vs geartrain

gearing and geartrain both are nouns.

Word	Noun	Adjective	Verb	Adverb
gearing	Yes	No	No	No
geartrain	Yes	No	No	No

As nouns, gearing and geartrain are synonyms defined as:

gearing and geartrain: wheelwork consisting of a connected set of rotating gears by which force is transmitted or motion or torque is changed

Other synonyms of gearing include gear, power train, train.

gearing (noun)	geartrain (noun)
wheelwork consisting of a connected set of rotating gears by which force is transmitted or motion or torque is changed	wheelwork consisting of a connected set of rotating gears by which force is transmitted or motion or torque is changed