From Longman Dictionary of Contemporary Englishldoce_276_apylonpy‧lon /ˈpaɪlən $ -lɑːn, -lən/ noun [countable] 1 TPEa tall metal structure that supports wires carrying electricity2 
American EnglishTTR one of a set of plastic cones placed on a road to control traffic and protect people working there
American EnglishTTR one of a set of plastic cones placed on a road to control traffic and protect people working thereExamples from the Corpus
pylon• For selection, a pylon is a minor provocation.• The skyline is dominated not by spires, but pylons.• There is nothing uglier than a redundant ski-tow out of season, with its pylons marching up a scarred, broken hillside.• A crew chief and gunner in the pockets behind them manned the two machine guns on the new pylon mounts.• Near the bottom, the trail swooped around the pylons of a chair lift.• Each stood at the ready, one eye on the pylon, the other on my raised arm.• What on earth can Mr Hague do to stop the pylons?• They position their pylons anywhere they choose and act as though they were still the strategic industry that they were once defined as.Origin pylon (1800-1900) Greek “gateway”, from pyle “gate” 