Longman Dictionary of Contemporary English
Douglas Harper's Etymology Dictionary
Wiktionary
a. expressing disapproval or being critical of oneself, especially modestly or humorously so.
WordNet
adj. conscious of your own shortcomings
Usage examples of "self-deprecating".
On weekends he would be seen paying out in the pubs around East London and Essex with a smile and his self-deprecating wit.
They were just two Air Force guys joshing with the other pilots, self-deprecating, almost witty.
Which is ridiculous, because Mark is totally perfect husband material, being completely sweet and thoughtful and funny and self-deprecating and totally the opposite of his horrible friend Cal the Modelizer in every way.
If it hadn't been for those damn' meddlesome posthumanists –" Her wrinkled, unnaturally aged face scowls at him furiously from underneath hair that has faded to the color of rotten straw, but he senses a subtext of self-deprecating irony that he doesn't understand.