An "oversized blazer" refers to a blazer or jacket that is intentionally larger or looser in fit than the usual size or style. It is meant to be deliberately oversized for a fashionable and relaxed look. Full definition
I have a particular liking for oversized blazers with statement buttons. (myfashionslashlife.com)
We've seen a lot of oversized check blazers trending but it's continuing down the line with more oversized blazers in check patterns but also monochromatic styles. (thefashionfolks.com)
I've had oversized blazers on the brain for a couple of weeks now. (thefashionfolks.com)