Something that is made up on the spot and given little time to gather and present. Usually referring to speeches that are given only a few minutes to prepare for.
I had to write an impromptu speech about Anal Cancer in 3 minutes without using the word 'ass' 'anus' 'shit' or 'hair'.
by Bastardized Bottomburp September 26, 2003
On the spot
When my chik walked in on me with my mistress, I had to make up an impromptu excuse for why my purple headed yogurt slinger was in her tuna taco.
by Vigilante DB October 25, 2003