9 letters · 17 points in Scrabble
adjective of an air current or wind; moving downward or down a slope because of cooling especially at night
originLearned borrowing from Ancient Greek καταιβατός (kataibatós, “down-going, descending”), from κατα- (kata-, “down”) + βαίνω (baínō, “to go”).
Etymology from Wiktionary, CC BY-SA 3.0