hobbing machine vs hobber

hobbing machine and hobber both are nouns.

Word	Noun	Adjective	Verb	Adverb
hobbing machine	Yes	No	No	No
hobber	Yes	No	No	No

As nouns, hobbing machine and hobber are synonyms defined as:

hobbing machine and hobber: a special type of milling machine used for gear cutting, cutting splines, and cutting sprockets.

hobbing machine (noun)	hobber (noun)
a special type of milling machine used for gear cutting, cutting splines, and cutting sprockets.	a special type of milling machine used for gear cutting, cutting splines, and cutting sprockets.