Chamaecyparis thyoides cha·mae·cy·paristhyoides uncommon noun 1. slow-growing medium-sized cedar of east coast of the United States; resembles American arborvitae Synonymssouthern white cedarcoast white cedarAtlantic white cedarwhite cypresswhite cedarChamaecyparis thyoides Related words Broader terms cedar Parts Chamaecyparis WordNet 2.1 (Princeton University). WordNet 2.1 Copyright Princeton University. All rights reserved.