An instance of digressing, especially a written or spoken passage that has no bearing on the main subject.(noun)
American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Use "digression" in a sentence
"Finally, in what can only be described as a digression from a digression, I feel compelled to mention that there is a multi-purpose, high quality item, within reach theoretically, that I cannot bring myself to buy, though I am convinced of its usefulness and value."
"Many novels contain what I call the digression-into-theme."
"But all this is what they call a digression; it has nothing to do with the dragon's teeth I am now narrating."