Dictionary Definition:
ud-aś √1. P. -aśnoti, (Subj. -aśnavat RV. v, 59, 4
• pf. -ānaṃśa RV. viii, 24, 12
• aor. -ā́naṭ and -ānaṭ, &c.), Ā. (3. du. -aśnuvāte ŚBr. iv, 2, 1, 26) to reach, attain, arrive at ŚBr
• to reach, be equal
• to overtake, surpass
• to master, rule RV