house dick vs shamus

house dick and shamus both are nouns.

Word	Noun	Adjective	Verb	Adverb
house dick	Yes	No	No	No
shamus	Yes	No	No	No

As nouns, shamus is a hypernym of house dick; that is, shamus is a word with a broader meaning than house dick:

house dick: a private detective employed by a hotel or retail store
shamus: someone who can be employed as a detective to collect information and assist in criminal investigations

Other hypernyms of house dick include operative, PI, private detective, private eye, private investigator, sherlock.

house dick (noun)	shamus (noun)
a private detective employed by a hotel or retail store	someone who can be employed as a detective to collect information and assist in criminal investigations