underthing From WikiWord, the free dictionary English Contents DefinitionsRelated wordsReferences Definitionsnoun(chiefly in the plural) An undergarment. Related wordsSynonymsundergarmentundersundershiftunmentionablesundergearundergownunderdressnethergarmentundershirtunderfrockundertrousersunderclothundertunicungarmentunderclothesunderwrap References Wiktionary — underthing Wikipedia — underthing