extemporal

adjective

ex·​tem·​po·​ral ek-ˈstem-p(ə-)rəl 

archaic

: extemporaneous

extemporally

ek-ˈstem-p(ə-)rə-lē 

adverb

Word History

Etymology

borrowed from Latin extemporālis, from ex tempore "on the spur of the moment, extempore" + -ālis -al entry 1

First Known Use

1570, in the meaning defined above