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
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