bollard

Etymology

From Middle English bollard, probably from Middle English bole (“tree trunk”), equivalent to bole + -ard (pejorative or diminutive suffix).

noun

1. (nautical) A strong vertical post of timber or iron, fixed to the ground and/or on the deck of a ship, to which the ship's mooring lines etc are secured.
   Today he had for bollard the unfinished monument half-erected to some all but forgotten anarchist. 1959, Mervyn Peake, Titus Alone
   He sat on a bollard, looking out across the water, a man more small and shabby than expected. 1965, Poul Anderson, The Star Fox
2. A similar post preventing vehicle access to a pedestrian area, to delineate traffic lanes, or used for security purposes.