player vs retreatant

player and retreatant both are nouns.

Word	Noun	Adjective	Verb	Adverb
player	Yes	No	No	No
retreatant	Yes	No	No	No

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

player (noun)	retreatant (noun)
a theatrical performer	a participant in a religious retreat
a person who participates in or is skilled at some game
someone who plays a music as a profession
a person who pursues a number of different social and sexual partners simultaneously
someone who takes part in an activity