1) The visible outline of a girl's ass created when she wearing
leggings with either a long shirt or short dress/skirt that showcases the bottoms of her cheeks where they meet the back of her thighs. Resulting in upside-down cleavage of the ass best appreciated when she's walking up stairs.
2) Summertime variation would include the same get up sans leggings and/or with short-shorts.
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)