Origin: Latin suffix -ous
Extemporaneous has 2 different meanings across 1 category:
with little or no preparation or forethought
"his ad-lib comments showed poor judgment"
"an extemporaneous piano recital"
"an extemporary lecture"
"an extempore skit"
"an impromptu speech"
"offhand excuses"
"trying to sound offhanded and reassuring"
"an off-the-cuff toast"
"a few unrehearsed comments"
With inadequate preparation or without advance thought; offhand.