A low tower, having a truncated pyramidal form, and flanking an ancient Egyptian gateway. [1913 Webster]
"Massive pylons adorned with obelisks in front." [1913 Webster]
A tower, commonly of steelwork, for supporting either end of a wire, as for a telegraph line, over a long span. [Webster 1913 Suppl.]
Formerly, a starting derrick (the use of which is now abandoned) for an aeroplane. [Webster 1913 Suppl.]

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OXFORD DICTIONARY

pylon, n.
1 a tall structure erected as a support (esp. for electric-power cables) or boundary or decoration.
2 a gateway, esp. of an ancient Egyptian temple.
3 a structure marking a path for aircraft.
4 a structure supporting an aircraft engine.

Etymology

Gk pulon f. pule gate

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THESAURUS

pylon

French door, antenna tower, archway, back door, barbican, barway, beacon, beam, belfry, bell tower, bulkhead, campanile, carriage entrance, cellar door, cellarway, colossus, column, cupola, derrick, dome, door, doorjamb, doorpost, doorway, fan marker, fire tower, flare path, front door, gate, gatepost, gateway, hatch, hatchway, lantern, lighthouse, lintel, marker, martello, martello tower, mast, minaret, monument, obelisk, observation tower, pagoda, pilaster, pillar, pinnacle, pole, porch, portal, porte cochere, postern, propylaeum, pyramid, racon, radar beacon, radio beacon, scuttle, shaft, side door, skyscraper, spire, standpipe, steeple, stile, storm door, stupa, television mast, threshold, tollgate, tope, tour, tower, trap, trap door, turnpike, turnstile, turret, water tower, wind cone, wind indicator, wind sock, windmill tower

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