serjeant-at-law vs barrister

serjeant-at-law and barrister both are nouns.

Word	Noun	Adjective	Verb	Adverb
serjeant-at-law	Yes	No	No	No
barrister	Yes	No	No	No

As nouns, barrister is a hypernym of serjeant-at-law; that is, barrister is a word with a broader meaning than serjeant-at-law:

serjeant-at-law: an English barrister of the highest rank
barrister: a British or Canadian lawyer who speaks in the higher courts of law on behalf of either the defense or prosecution

serjeant-at-law (noun)	barrister (noun)
an English barrister of the highest rank	a British or Canadian lawyer who speaks in the higher courts of law on behalf of either the defense or prosecution