It apparently is a word in America English, just not common: Merrium-Webster: Definition of bollard 1: a post of metal or wood on a wharf around which to fasten mooring lines

2: BITT sense 1

3 chiefly British : any of a series of short posts set at intervals to delimit an area (such as a traffic island) or to exclude vehicles.

Examples of bollard in a Sentence: Recent Examples on the Web "From 2017 to 2021, approximately 226 miles of 30-foot bollard fencing went up on federal lands in Arizona.— Clara Migoya, The Arizona Republic, 31 Dec. 2021 etc."

I never heard it before and I love arcane words. Thanks for the introduction!