oar vs boat paddle

oar and boat paddle both are nouns.

Word	Noun	Adjective	Verb	Adverb
oar	Yes	No	No	No
boat paddle	Yes	No	No	No

As nouns, boat paddle is a hyponym of oar; that is, boat paddle is a word with a more specific, narrower meaning than oar:

oar: an implement used to propel or steer a boat
boat paddle: a short light oar used without an oarlock to propel a canoe or small boat

Other hyponyms of oar include paddle, scull, scull, sweep, sweep oar.

oar (noun)	boat paddle (noun)
an implement used to propel or steer a boat	a short light oar used without an oarlock to propel a canoe or small boat