ex tempore
extempore
impromptu
ad libitum
spontaneously
ad lib
unpremeditated
cold
extemporaneously
extemporarily
unprepared
off the cuff
offhanded
off-the-cuff
extemporaneous
ad-lib
unrehearsed
offhand
extemporary
out of the blue
unfacilitated
nonfacilitated
pending
unpracticed
ad-libbed
unexperimented
unconsidered
unprocedurally
nonmanual
indextrous
unprepped
unaccomplished
off the top of one's head
offhandedly
unsuccessfully
unaided
nonprocessed
unenfolded
unplanished
unprocedural
methodless
unsupplicated
unripe
unwinded
workmanlike
unfinalized
unattempted
nonpreformed
uninculcated
on the hoof