Definition of a clothespole was not as common as expected, as most washing lines don't require them. The standard in Cardiff used to be a tall line post at one end of the garden, with a pulley at the top (say 15ft) and a cleat(tying off point) at about 5ft. The other end of the top line was either tied off to a cleat on the house wall, or passed though a pulley attached to the wall, to be tied off to a cleat at about 5ft. By lowering the line (from either end if with 2 pulleys) the line could be loaded or unloaded, and then raised to catch the most of the sun and wind at a height where shade fro walls or houses was less of a problem.
On very windy days, there was also a lower line at about 5ft6in. which was secured at both ends. As long as this was stretched taut, there was no nead for a clothesprop to raise the middle of the line.

These days the definition is needed because of the proliferation of 'rotary' clothes lines.

Nigel