- bar
- bee
- boom
- boutade
- brainstorm
- branch
- brand
- capriccio
- caprice
- case
- character
- chevron
- cocker
- comicality
- composition
- conceit
- crab
- crackpot
- crank
- craze
- crazy idea
- crotchet
- damp
- deflection
- deviant
- ding-a-ling
- drollness
- endomorphism
- fad
- fancy
- fantastic notion
- fantasy
- fey
- flimflam
- fool notion
- freak
- freakish
- freakish inspiration
- globulin
- gyrate
- habit
- harebrained idea
- hemoglobin
- hothead
- humor
- idiosyncratic
- jimmy
- joking
- kicker
- kink
- limb
- loner
- maggot
- makeup
- megrim
- mesomorphy
- mind
- morale
- notion
- odd
- passing fancy
- pedal
- queer duck
- quirk
- quoin
- raillery
- repartee
- sarcasm
- showeriness
- soothe
- toy
- treadle
- treadmill
- twist
- type
- vagary
- wacky
- waggishness
- way
- whim
- whimsy
- whim-wham
- whiner