elfin /ˈɛlfɪn/noun 3adjective 2forms 3 noun3 •An elf; an inhabitant of fairy-land. •Any of the butterflies in the subgenus Incisalia of the North American lycaenid genus Callophrys. •A little urchin or child. adjective2 •Of or relating to elves. •Resembling an elf or elves, especially in tiny size or features.I first met Demis Hassabis, the remarkable human, in the mid-2010s: an elfin figure with dark hair falling forward toward angular eyebrows, his face framed by standard-issue spectacles. — 2026 formselfins · more elfin · most elfin