desk sergeant vs station keeper

desk sergeant and station keeper both are nouns.

Word	Noun	Adjective	Verb	Adverb
desk sergeant	Yes	No	No	No
station keeper	Yes	No	No	No

As nouns, desk sergeant and station keeper are synonyms defined as:

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

Other synonyms of desk sergeant include deskman.

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