riff
noun
a melodic phrase, often constantly repeated, forming an accompaniment or part of an accompaniment for a soloist.
Used to describe an action that began in the past, has continued continuously, and is still in progress.
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
Colbert began his last Report by riffing on what pop-culture commentators have been riffing on all week, his show’s legacy, though tongue-in-cheek.
From Time ● Dec. 19, 2014