hard subtitle vs hardsub

hard subtitle and hardsub both are nouns.

Word	Noun	Adjective	Verb	Adverb
hard subtitle	Yes	No	No	No
hardsub	Yes	No	No	No

As nouns, hard subtitle and hardsub are synonyms defined as:

hard subtitle and hardsub: (often plural) a subtitle whose text is irreversibly merged in original video frames.

hard subtitle (noun)	hardsub (noun)
(often plural) a subtitle whose text is irreversibly merged in original video frames.	(often plural) a subtitle whose text is irreversibly merged in original video frames.