A primitive form in the Gnomish Lexicon of the 1910s with derivatives meaning “day” (GL/38). There were a variety of different roots for “day” in later writings such ᴹ√AR or √UR.
Early Primitive Elvish
ara
root. (be) dry
ara
root. spread, extend sideways
āra
noun. smith
ʒara
root. spread, extend sideways; wide places
ðana
root. day
A root in the Qenya Lexicon of the 1910s meaning “(be) dry” (QL/32). Given the many uses to which √AR was put later, it is unlikely this sense remained valid in Tolkien’s later writing; the later root ᴹ√PARAK and its derivatives is probably better for the purposes of Neo-Eldarin writing.