1) Animal tissue 2) Cartilage 3) Cartilage in meat 4) Chewy part of meat 5) Exclusively Saxon word 6) Exclusively Anglo word 7) Inedible meat part 8) Steak defect 9) Steak remains 10) Steak throwaway 11) Tough bit in a steak 12) Tough elastic tissue 13) Tough meat stuff 14) Tough stuff in meat 15) Tough tissue Found on https://www.crosswordclues.com/clue/gristle
Gris'tle noun [ Middle English gristel , gristil , Anglo-Saxon gristl ; akin to OFries. gristel , grestel . Perh. a dim. of grist but confer Old High German krustila , krostela . Confer Grist .] (Anat.) Cartilage. See Cartil... Found on http://www.encyclo.co.uk/webster/G/59