Dictionary Definition:
arcís n. ray of light, flame, light, lustre RV. (once. Pl. arcī́nṣi RV. vii, 62, 1) AV. ŚBr. &c
• (is), f. id. ŚBr. ii Up. &c., (is), N. of the wife of Kṛiśāśva and mother of Dhūmaketu BhP