Slang One that is remarkable or extraordinary, as in size or quality: had a dilly of a fight. (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 "dilly" in a sentence
"I think you mean it's a "dilly" of an article, rather than a "ditty" of an article."
"I have no time to describe to you what this plan was except to say that it was a "dilly", but when I hear complaints that these very expensive Royal Commission reports are almost always pigeon-holed I ask myself what else could be done with the "Solution" proposed by the last Royal Commissioner to sit in judgment on Ontario's forests."
"Any kind of dilly-dallying, that’s the government."