11 letters · 15 points in Scrabble
verb have strong suppressed feelings
verb burn slowly and without a flame
adjective showing scarcely suppressed anger; - James Hensel
originEtymology tree English smoulder Proto-Indo-European *-onts Proto-Germanic *-ndz Proto-West Germanic *-andī Old English -ende Middle English -ynge English -ing English smouldering From smoulder + -ing.
Etymology from Wiktionary, CC BY-SA 3.0