In addition to, and to clarify, the other definition:
A person (often female) is dressed down when she is wearing clothes that do not accentuate her voluptuous parts (if any).
Despite her attempts to dress down by wearing long pants and a coat, that shit was still poppin' out all over the place!
The act of forgetting that it is dress downday and arriving in your regular work wear.
Joey turned up to work in his normal work clothes whilst all his colleagues had remembered to come in casual clothing, Poor Joey has some kind of Dress Down Syndrome.
Fogey/fogy /fougi/ sl. (early 18C+, orig. Scot) old-fashioned, stuck-in-the mud.
Person with old fashioned ideas which he is unwilling to change: Come to the disco and stop being such an old fogey!
You think me an old fogeyand an old tory, his thoughtful voice said. I saw three generations since O’Connel’s time. I remember the famine. Do you know that the orange lodges agitated for repeal of the union twenty years before O’Connel did or before the prelates of your communion denounced him as a demagogue? You fenians forget some things. (James Joyce, Ulysses. Penguin Books,1992. p. 38)