casting vs engine block

casting and engine block both are nouns.

Word	Noun	Adjective	Verb	Adverb
casting	Yes	No	No	No
engine block	Yes	No	No	No

As nouns, engine block is a hyponym of casting; that is, engine block is a word with a more specific, narrower meaning than casting:

casting: object formed by a mold
engine block: a metal casting containing the cylinders and cooling ducts of an engine

Other hyponyms of casting include death mask, block, cylinder block, life mask.

casting (noun)	engine block (noun)
the act of creating something by casting it in a mold	a metal casting containing the cylinders and cooling ducts of an engine
the act of throwing a fishing line out over the water by means of a rod and reel
the choice of actors to play particular roles in a play or movie
object formed by a mold