offhanded
offhand
offhandedly
unconsidered
extemporaneously
extempore
extemporarily
on the hoof
cold
extemporaneous
ready-made
unbeginningly
off the cuff
ex tempore
acephalous
off-hand
thoughtlessly
notionless
underivedly
blindly
off the top of one's head
unprepared
extemporary
formulation
off-the-cuff
conceptualisation
conceptualization
spontaneously
ad lib
unrehearsed
ad libitum
ad-lib
impromptu
unplanned
unawares
preparatively
unconscious
unpremeditated
inventionless
introductionless
designlessly
unthought
unwritten
spontaneous
prelogical
deep-laid
autoschediasm
unprologued
unthoughtful
improvisation