subcutaneous vs hypodermic

subcutaneous is not a noun while hypodermic is a noun.

Word	Noun	Adjective	Verb	Adverb
subcutaneous	No	Yes	No	No
hypodermic	Yes	Yes	No	No

As adjectives, subcutaneous and hypodermic are synonyms defined as:

subcutaneous (noun)	hypodermic (noun)
	a piston syringe that is fitted with a hypodermic needle for giving injections

subcutaneous (adjective)	hypodermic (adjective)
relating to or located below the epidermis	relating to or located below the epidermis