Ull vs Ullr

Ull and Ullr both are nouns.

Word	Noun	Adjective	Verb	Adverb
Ull	Yes	No	No	No
Ullr	Yes	No	No	No

As nouns, Ull and Ullr are synonyms defined as:

Ull and Ullr: (Norse mythology) one of the Aesir known for his beauty and skill with bow and skis; son of Sif and stepson of Thor

Ull (noun)	Ullr (noun)
(Norse mythology) one of the Aesir known for his beauty and skill with bow and skis; son of Sif and stepson of Thor	(Norse mythology) one of the Aesir known for his beauty and skill with bow and skis; son of Sif and stepson of Thor