/ Thesaurus / E Synonyms of eucalyptus regnans Find synonyms for: Noun1. mountain ash, Eucalyptus regnans, eucalyptus, eucalypt, eucalyptus treeusage: tree having wood similar to the alpine ash; tallest tree in Australia and tallest hardwood in the worldWordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: nefarious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language