serum vs antiserum

serum and antiserum both are nouns.

Word	Noun	Adjective	Verb	Adverb
serum	Yes	No	No	No
antiserum	Yes	No	No	No

As nouns, antiserum is a hyponym of serum; that is, antiserum is a word with a more specific, narrower meaning than serum:

serum: an amber, watery fluid, rich in proteins, that separates out when blood coagulates
antiserum: blood serum containing antibodies against specific antigens; provides immunity to a disease

Other hyponyms of serum include milk whey, whey.

serum (noun)	antiserum (noun)
an amber, watery fluid, rich in proteins, that separates out when blood coagulates	blood serum containing antibodies against specific antigens; provides immunity to a disease