calima adj. "bright" (VT42:32); cf. ancalima; in PE17:56, arcalima appears as another superlative "brightest" (see ar- #2).
Quenya
ar-
brightest
calima
bright
ancalima
most bright, brightest
ancalima adj. "most bright, brightest", sc. calima "bright" with a superlative or intensive prefix (LotR2:IV ch. 9; see Letters:385 for translation). Ancalima imbi eleni "brightest among stars", also [ancalima] imb' illi "brightest among all" (VT47:30). Fem. name Ancalimë, *"Most Bright One", also masc. Ancalimon (Appendix A). Tar-Ancalimë, a Númenorean Queen (UT:210)
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 Tolkiens work. See an- #2, am- #2.