Denshi Jisho — Online Japanese dictionary

或 ある a certain ...; some ...
Common word, Pre-noun adjectival, Usually written using kana alone 
或る ある a certain ...; some ...
Pre-noun adjectival, Usually written using kana alone 
或は あるは or; possibly
Irregular okurigana usage, Adverb, Conjunction, Expression, Usually written using kana alone 
或日 あるひ one day (e.g. "one day while studying, ..")
Irregular okurigana usage, Noun 
或る日 あるひ one day (e.g. "one day while studying, ..")
Noun 
或は あるいは or; possibly
Irregular okurigana usage, Adverb, Conjunction, Expression, Usually written using kana alone 
或いは あるいは or; possibly
Common word, Adverb, Conjunction, Expression, Usually written using kana alone 
或る種 あるしゅ certain; some kind of; some sort of; of sorts
No-adjective 
或る時 あるとき once (i.e. "once, when I was studying ..")
Noun 
或る人 あるひと someone (unspecified, but someone in particular); a certain person
Noun 
或る程度 あるていど to some extent; to a certain extent
Expression, No-adjective, Adverb 
或る程度まで あるていどまで to some degree; up to a point; to some extent
Expression 

You can also

Look up kanji details for 或 あるいは.

Try a Yahoo Jisho search for 或 あるいは .
Try a Goo Jisho search for 或 あるいは .
Try a Google search for 或 あるいは .