PYLON (2)

Py″lon, n. 1. 1. A tower, commonly of steelwork, for supporting either end of a wire, as for a telegraph line, over a long span.
2. 2. (Aëronautics) (a) Formerly, a starting derrick (the use of which is now abandoned) for an aëroplane. (b) A post, tower, or the like, as on an aërodrome, or flying ground, serving to bound or mark a prescribed course of flight.