impulsive
instinctive
intuitive
natural
unprompted
unscripted
ad lib
arbitrary
automated
automatic
automatous
autonomous
bat
baton
billy
billy club
bludgeon
casual
club
cybernated
discretional
discretionary
elective
extemporaneous
extempore
free
free will
gratuitous
gut
ill-advised
ill-considered
ill-devised
immediate
impetuous
impromptu
improvised
inadvertent
indeliberate
independent
inherent
innate
instinctual
involuntary
libidinal
mace
mechanical
nightstick
nonmandatory
off the cuff
offered
offhand
spontaneous combustion
poetic
sincere
sudden
contemporaneous
extraneous
miscellaneous
percutaneous
simultaneous
labored