ar- (2), also ari-, prefix for superlative (compare arya #1, 2), hence arcalima “brightest”, arimelda *”dearest” (PE17:56-57). In the grammar described in the source, this prefix was to express superlative as the highest degree (in actual comparison), whereas the alternative prefix an- rather expressed “very” or “exceedingly” with a more purely augmentative or adverbial force, but these distinctions do not seem to have been clearly present at all stages of Tolkien’s work. See an- #2, am- #2.
áranoun "dawn" (AR1). According to VT45:6, ára is also the name of the long vowel carrier of the Tengwar system; it would be the first letter of the word ára if spelt in Tengwar.
araprep.(and adv.?) "outside, beside, besides" (AR2, VT49:57). According to VT45:6, the original glosses were "without, outside, beside", but Tolkien emended this. Arsë “he is out”, VT49:23, 35, 36. As for ar(a), see ar #1. – VT49:25 lists what seems to be ar(a) combined with various pronominal suffixes: Singular anni > arni *”beside me”, astyë *“beside you” (informal), allë *“besides you” (formal), arsë *”beside him/her”, plural anwë > armë *“beside us” (exclusive), arwë *“beside us” (inclusive), astë > ardë *“beside you” (plural), astë > artë *“beside them”; dual anwet > armet *“beside us (two)”. (Here Tolkien presupposes that ara represents original ada-.) The same source lists the unglossed forms ari, arin that may combine the preposition with the article, hence *“beside the” (VT49:24-25)