Lambent is not quite smouldering, that is rather too va-va-voom for the word. Lambent speaks of something evanescent, glowing and attractive.
Lambent: gleaming or flickering with a soft radiance. From the Latin lambere, ‘to lick’. From Greek laptein ‘to sip, lick’, Old English lapian, ‘to lick, lap up’.
(Image: 生生不息的森林 (Living Forest), Françoise Gilot, 1977)