Entry 2 senses · 2 variants Webster, 1913 Uprush · Up·rush · IPA /ˈʌpɹʌʃ/ v. i. n. 01 v. i. To rush upward. 1. To rush upward. 02 n. Act of rushing upward; an upbreak or upburst; as, an uprush of lava. 1. Act of rushing upward; an upbreak or upburst; as, an uprush of lava.