(intransitive, chiefly British) Alternative form of smolder
1895, H. G. Wells, The Time Machine Chapter XII don't know if you have ever thought what a rare thing in the absence of man and in a temperate climate, flames must be. The sun's heat is rarely strong enough to burn even when focussed by dewdrops, as is sometimes the case in more tropical districts. Lightning may blast and blacken, but it rarely gives rise to widespread fire. Decaying vegetation may occasionally smoulder with the heat of its fermentation, but this again rarely results in flames. Now, in this decadent age the art of fire-making had been altogether forgotten on the earth. The red tongues that went licking up my heap of wood were an altogether new and strange thing to Weena.