extemporaneously is a form of:

Extemporaneous



adjective
1.
(unrehearsed, offhand, impromptu) ដោយឥតព្រៀងដែលទុកមុន, រាន់, ដែលធ្វើឥតគិតទុក
ENGLISH MEANING
adjective
1.
Composed, performed, or uttered on the spur of the moment, or without previous study; unpremeditated; off-hand; extempore; extemporary; as, an extemporaneous address or production.