ageing vs grizzled

ageing

adj

  • UK, Australia, and New Zealand standard spelling of aging. 

noun

  • UK, Australia, and New Zealand standard spelling of aging. 

grizzled

adj

  • greyed, old 

  • streaked or mixed with grey; grizzly; griseous 

  • grey or partly grey 

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