0 done or said without earlier planning or preparation -- 無準備的，即興的
an impromptu party/performance 臨時晚會／即興表演
Waving a filthy fan, he swaggers his way into the middle of the arena, and delivers some impromptu verses.
Finally, in order to evaluate the foreign learners' command of gender in impromptu unassisted output, we obtained examples of their spontaneous written prose.
The second year extends students' shared socio-cultural knowledge through learning the standard jazz repertoire and performing together in impromptu and fluid bands.
Nor are they, it must be said, free from those defects which belong to such impromptu inspirations.
The more affluent, meanwhile, set aside rooms in their homes for use as impromptu chapels and heard services with greater frequency, albeit at greater risk.
There is an element of the impromptu about it, even of serendipity.
These entertainments may not be impromptu, but not all are contrived paddywackery.
In impromptu speaking, proximity agreement results from the halo effect of whatever has gone just before, and does not seem to provide a grammatical distraction.
