Improv is performance invented on the spot, with no script at all. The audience shouts a suggestion and the scene begins.
It is short for improvisation, and comedy clubs, drama classes and workshops all use the short form. The first rule of it is to accept whatever your partner offers, which performers call saying yes and. Music has improvisation too, and jazz is built on it. The verb is improvise, which also means to make do with whatever is at hand, as in improvising a splint.
1nounimprovUnscripted performance created on the spot.
“She teaches improv on Thursday evenings.”
a clipping of improvisation and improvise.
Etymology from Wiktionary, CC BY-SA