extemporaneous

a. 无准备的, 即席的, 临时的
【医】 临时的, 当时的

副词:extemporaneously 名词:extemporaneity 

ex.tem.po.ra.ne.ous

adj.（形容词）
Carried out or performed with little or no preparation; impromptu:
即兴的：毫无准备的或稍作准备就执行或表演的；即兴的：
例句：
an extemporaneous piano recital.
即兴钢琴独奏

Prepared in advance but delivered without notes or text:
不用讲稿的：事前有所准备而不带笔记或本文的：
例句：
an extemporaneous speech.
不用讲稿的演讲

Skilled at or given to unrehearsed speech or performance:
善于即兴讲话的：擅长于或倾向于即兴演说或即兴表演的：
例句：
an accomplished extemporaneous speaker.
一位高明的即席演讲者

Provided, made, or adapted as an expedient; makeshift:
临时的，权宜的：作为权宜之计而提供的、制作的或使用的；权宜的：
例句：
an extemporaneous policy decision.
一个权宜的政策决定


来源：
From Late Latin extempor3neus
源自 后期拉丁语 extempor3neus
from Latin ex tempore * see extempore
源自 拉丁语 ex tempore *参见 extempore

【引伸】
extem.porane.ity

extem.pora.neously
adv.（副词）
extem.pora.neousness
n.（名词）
<参考词汇><同义词>extemporaneous,extemporary,extempore,impromptu,offhand,unrehearsed,unpremeditated,ad-libThese adjectives mean spoken, performed, done, or composed with little or no preparation or forethought.Extemporaneous, extemporary, and extempore most often apply to discourse, as a public speech, that is delivered without the assistance of a written text, though it may have been planned in advance:
这些形容词的意思是未经准备或构思而演讲的、表演的、进行的或谱写的。Extemporaneous，extemporary 和 extempore 常适用于演讲，如公共演说， 虽然这可能经过提前筹划但演讲时却不需书面材料的帮助：
例句：
an extemporaneous address;
即兴演说；

例句：
an extemporary lecture;
即兴讲座；

例句：
an extempore skit.
即兴小品。

Impromptu even more strongly suggests action or expression that comes on the spur of the moment in response to an unforeseen need:
Impromptu 更强烈地表现对意料之外的需要所做出的相应的动作或表现：
例句：
an impromptu speech;
即席讲话；

例句：
an impromptu dinner.
便饭。

Offhand implies not only spontaneity but also a casual or even cavalier manner:
Offhand 不但表示自发的，也表示不经意的甚至漫不经心的举止的：
例句：
an offhand remark. What isunrehearsed is said or done without rehearsal or practice though not necessarily without forethought:
随意的评论。 所谓unrehearsed ，就是未经复述或练习就说或做的， 虽然没有不构思的必要：

例句：
a few unrehearsed comments.
未经练习的评论。

Unpremeditated applies to action taken without prior thought or plan;often the term implies impulsiveness prompted by strong feeling:
Unpremeditated 表示未经提前思考或计划而采取的行动；这个词常表示在强烈情感的怂恿下而造成的冲动：
例句：
asked an unpremeditated question. Something that isad-lib is spontaneous and improvised and therefore not part of a prepared script or score:
随口提出一个问题。 ad-lib 的事物是自发产生的和即兴而作的， 因而不是预先准备的手稿或记录的部分：

例句：
an ad-lib joke;
随口开的玩笑；

例句：
an ad-lib solo.
即兴的独奏