fiberglass vs fibreglass

fiberglass

fibreglass

verb
  • To apply fibreglass to. 

noun
  • Silica based glass extruded into fibers that possess a length at least 1000 times greater than their width. 

  • A composite material made from fine fibres of spun glass held together with resin. 

How often have the words fiberglass and fibreglass occurred in a corpus of books? (source: Google Ngram Viewer )