Improvise
Definition 1 of 4
Pro Tip 1/2
Unexpected Situations
Use 'improvise' when you have to speak or react suddenly without time to prepare. When the host didn't show, I had to improvise the entire presentation.
Pro Tip 2/2
Speech Flexibility
You might need to 'improvise' if the audience's reaction is different from what you expected. They looked bored, so he improvised some jokes into his talk.