Riffing is a term that is often used in music and comedy to describe improvisational play. Some synonyms for the word riffing are jamming, freestyling, improvising, spur-of-the-moment, and riffing off. Jamming is a musical term that refers to a group of musicians coming together to play without a set plan or structure. Freestyling is commonly used in hip hop to describe improvising lyrics on the spot. Improvising is the broadest term, as it can be applied to any situation where one is creating on the fly. Spur-of-the-moment and riffing off both suggest spontaneity and an ability to respond creatively in the moment.