The Tocharian B word waiw-
Word waiw-
w ai w
IPA wɐiw
Meaning moisten

Comments
Douglas Q. Adams, “Etymological Dictionary of Tocharian B”, 1999, Brill

Other words that might be of interest
war ‘water’, swese ‘rain’, cake ‘river’, lyam ‘lake’, samudtär ‘sea’, karītstse ‘wet’, asāre ‘dry’, tsrerme ‘ditch’, murye ‘ditch, irrigation’, pält- ‘drip’, kärkkālle ‘marsh, swamp’, kaumiye ‘pond’, āp ‘river’