oar vs scull

oar and scull both are nouns.

Word	Noun	Adjective	Verb	Adverb
oar	Yes	No	No	No
scull	Yes	No	Yes	No

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

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

oar (noun)	scull (noun)
an implement used to propel or steer a boat	a racing shell that is propelled by sculls
	each of a pair of short oars that are used by a single oarsman
	a long oar that is mounted at the stern of a boat and moved left and right to propel the boat forward

oar (verb)	scull (verb)
	propel with sculls