- aberration
- abnormal
- abnormality
- bee
- boutade
- brainstorm
- brand
- buff
- bug
- capriccio
- caprice
- cast
- character
- characteristic
- conceit
- crackpot
- crank
- craze
- crazy idea
- crosspatch
- crotchet
- cut
- deformity
- deviation
- earmark
- eccentric
- eccentricity
- fad
- fanatic
- fancy
- fantastic notion
- fantasy
- flavor
- flimflam
- fool notion
- freak
- freakish inspiration
- habit
- harebrained idea
- humor
- idiosyncrasy
- impress
- impression
- individualism
- irregularity
- keynote
- kink
- kook
- maggot
- mark
- marking
- megrim
- minauderie
- mold
- monstrosity
- nature
- notion
- oddball
- oddity
- passing fancy
- peculiarity
- property
- quality
- quirk
- recluse
- screw
- shape
- smack
- stamp
- taint
- token
- toy
- trademark
- trick
- turn
- twist
- type
- vagary
- way
- whim
- whimsy
- whim-wham
- zealot