According to Riddle Spot, the answer to the riddle What goes up the chimney down but cannot go down the chimney up? is an umbrella. An umbrella is very thin and narrow when it is down, so it can fit through the narrow opening of a chimney. When an umbrella is up, however, it is too large to fit through the same narrow opening.
frag. n. A fragmentation grenade. tr.v. fragged, fragÂ·ging, frags. To wound or kill (a fellow soldier) by throwing a grenade or similar explosive at the victim: He got fragged.
The term negging seems to be widely misunderstood. The Freakonomics blog says: Under particular discussion is a pickup technique that Mystery advocates known as negging  a move that involves interjecting an insult during an initial conversation with a woman. No, that is not correct. If the woman feels insulted, then negging won't work at all.