Suggestive of an elf in strangeness and otherworldliness:
— Thunderbolts quivered with elfin flares of heat lightning.

synonym: fey.

Roget 193: little; small etc. (in quantity) 32; minute, diminutive, microscopic; microzoal; inconsiderable etc. (unimportant) 643; exiguous, puny, tiny, wee, petty, minikin^†, miniature, pygmy, pigmy^†, elfin; undersized; dwarf, dwarfed, dwarfish; spare, stunted, limited; cramp, cramped; pollard, Liliputian, dapper, pocket; portative^†, portable; duodecimo^†; dumpy, squat; short etc. 201.    impalpable, intangible, evanescent, imperceptible, invisible, inappreciable, insignificant, inconsiderable, trivial; infinitesimal, homoeopathic^†; atomic, subatomic, corpuscular, molecular; rudimentary, rudimental; embryonic, vestigial.    weazen^†, scant, scraggy, scrubby; thin etc. (narrow) 203; granular etc. (powdery) 330; shrunk etc. 195; brevipennate^†.    ... show more

Small and delicate:
— She was an elfin creature--graceful and delicate.
— Obsessed by things elfin and small.

synonym: elflike.

Roget 980: demonic, demonical, impish, demoniacal; fiendish, fiend-like; supernatural, weird, uncanny, unearthly, spectral; ghostly, ghost-like; elfin, elvin^†, elfish, elflike^†; haunted; pokerish [U.S.].    possessed, possessed by a devil, possessed by a demon.    ... show more

Relating to or made or done by or as if by an elf.

Usually good-naturedly mischievous:
— Perpetrated a practical joke with elfin delight.

synonyms: elfish, elvish.