A "dress jacket" is a type of formal coat or blazer that is worn on special occasions or when you want to look more fancy or dressed up. Full definition
I like to wear them under dress jackets because at my age, I get hot (not in a good way) lol. (fashionbeyondforty.com)
All you need to do is checking a host of filters and select the best black royal blue prom dresses jacket in a simple way. (au.dhgate.com)
There was a lot to see and admire at the next stage of the show when the catwalk was taken over by storm with black pleated skirts and high collared white jackets, patterned dress jackets with notched necklines, two piece suits consisting of straight pants and V - neck jackets (not the interesting effect the side buttons make), high waisted white maxi skirts with lacy tops, high collared loose dresses and so on. (heduy.com)