deskman vs desk sergeant

deskman and desk sergeant both are nouns.

Word	Noun	Adjective	Verb	Adverb
deskman	Yes	No	No	No
desk sergeant	Yes	No	No	No

As nouns, deskman and desk sergeant are synonyms defined as:

deskman and desk sergeant: the police sergeant on duty in a police station

Other synonyms of deskman include station keeper.

deskman (noun)	desk sergeant (noun)
the police sergeant on duty in a police station	the police sergeant on duty in a police station