switch engine vs donkey engine

switch engine and donkey engine both are nouns.

Word	Noun	Adjective	Verb	Adverb
switch engine	Yes	No	No	No
donkey engine	Yes	No	No	No

As nouns, switch engine and donkey engine are synonyms defined as:

switch engine and donkey engine: a locomotive for switching rolling stock in a railroad yard

switch engine (noun)	donkey engine (noun)
a locomotive for switching rolling stock in a railroad yard	(nautical) a small engine (as one used on board ships to operate a windlass)
	a locomotive for switching rolling stock in a railroad yard