extempore

形容词 extempore:

1. with little or no preparation or forethought
   同义词：ad-lib, extemporaneous, extemporary, impromptu, offhand, offhanded, off-the-cuff, unrehearsed

副词 extempore:

1. without prior preparation
   同义词：extemporaneously, extemporarily

ex.tem.po.re

adj.（形容词）
Spoken, carried out, or composed with little or no preparation or forethought.See Synonyms at extemporaneous
当场的，即兴的，无准备的：未经或很少准备或构思而讲的，做的或谱写的参见 extemporaneous
adv.（副词）
In an extemporaneous manner.
无准备的，当场的

来源：
Latin ex tempore
拉丁语 ex tempore
ex [of] * see ex-
ex […的] *参见 ex-
tempore [ablative of] tempus [time]
tempore [] tempus的夺格 [时间]