railway locomotive vs locomotive engine

railway locomotive and locomotive engine both are nouns.

Word	Noun	Adjective	Verb	Adverb
railway locomotive	Yes	No	No	No
locomotive engine	Yes	No	No	No

As nouns, railway locomotive and locomotive engine are synonyms defined as:

railway locomotive and locomotive engine: a wheeled vehicle consisting of a self-propelled engine that is used to draw trains along railway tracks

Other synonyms of railway locomotive include engine, locomotive.

railway locomotive (noun)	locomotive engine (noun)
a wheeled vehicle consisting of a self-propelled engine that is used to draw trains along railway tracks	a wheeled vehicle consisting of a self-propelled engine that is used to draw trains along railway tracks