Posted on 18th July 2013 by melyn Kostrel is the Cornish word for flask Yes, flask in Cornish is kostrel Share this:Click to share on Twitter (Opens in new window)Click to share on Facebook (Opens in new window) Related Post navigationPrevious post: Diwysygneth is the Cornish word for diligenceNext post: Dowrliw is the Cornish word for water-colour