engineering vs subject area

engineering and subject area both are nouns.

Word	Noun	Adjective	Verb	Adverb
engineering	Yes	No	No	No
subject area	Yes	No	No	No

As nouns, subject area is a hypernym of engineering; that is, subject area is a word with a broader meaning than engineering:

engineering: the discipline dealing with the art or science of applying scientific knowledge to practical problems
subject area: a branch of knowledge

Other hypernyms of engineering include bailiwick, discipline, field, field of study, study, subject, subject field.

engineering (noun)	subject area (noun)
the practical application of technical and scientific knowledge to commerce or industry	a branch of knowledge
a room (as on a ship) in which the engine is located
the discipline dealing with the art or science of applying scientific knowledge to practical problems