Definitions:

1. relating to or made or done by or as if by an elf adjective
   • elfin bells
2. small and delicate adjective
   • They were an elfin creaturegraceful and delicate.
3. suggestive of an elf in strangeness and otherworldliness adjective
   • thunderbolts quivered with elfin flares of heat lightning
4. usually good-naturedly mischievous adjective
   • perpetrated a practical joke with elfin delight

Synonyms:

• elfish
• elflike
• elvish
• fey