1. An unnatural movement of the fly due to having cast straight across a current. The flyline pulls the fly forcing it to drift unnaturally, either inducing a take or putting the fish down (entirely depending on how you behaved during your last life). The best solution is of course to try and overcome the imprints previous lives have left upon you. Failing this try a presentation cast.
2. The braking system incorporated in some flyreels. This is a very useful attribute for trout fishing since if you were trout fishing at Rutland, say, and were to suddenly and unexpectedly hook a large trevally, you could clamp the drag down hard and snap the tippet.
3. One of the things not widely discussed in angling circles is the transvestite element that appears to be creeping into the stillwater flyfishing scene. On special occasions stillwater anglers (especially misguided-guided competition ones) hold special private raves and dress up in women's underwear.

Braking mechanism on the reel. drag system - what we call a drag after the marketing division of the reel manufacturer kicked the engineers out of the advertising meeting.

A multi purpose term in the angling world.

1. The tension applied to the line by a mechanism on the reel to make it harder for the fish to swim away. Could be a click-pawl, disc, a piece of leather or the palm of the hand. Too much drag can cause the line to break.
   
2. Inhaling the smoke from a cigarette. An act performed by smokers that is said to calm the nerves, and observed amongst anglers especially after the line has broken as described above.
   
3. The movement of the fly on or in the water that is at variance with the current causing an unnatural movement which is unattractive to fish. Visible as a bow wave around the fly but usually is more subtle. One school of thought has it that drag is not so much unattractive to fish but that it causes the fish to misjudge the take.
   
4. A boring period of time experienced by fly anglers who cannot get the fly to drift at the same speed as the current
   
5. Clothing worn by transvestites. Transvestites do not like angling because the clothing worn by both sexes is identical.
   
6. A very fast car race. An example is when a group of anglers are travelling on a weekend fishing trip to a far flung location on Friday night.
   

Courtesy of Ken