Breadcrumb Home > Thesaurus > U Synonyms of upcast Find synonyms for: Noun 1. upcast, air passage, air duct, airway usage: air passage consisting of a ventilation shaft through which air leaves a mine WordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved.Definition and meaning of upcast (Dictionary) TrendingHere are the facts and trivia that people are buzzing about. Chinese New Year History, Meaning, and Celebrations Current Events This Week: February 2024 Valentine's Day Valentine's Day History Mardi Gras 30 "Charlie and the Chocolate Factory" Quotes ✖ Related Content Daily Word Quiz: soupon Analogy of the Day: Today’s Analogy Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language