stonehard

• stone-hard

From Middle English ston-hard, ston-harde, from Old English *stānheard (attested in names: stanhard, stanart, stannard, etc.), equivalent to stone +‎ hard.

stonehard (not comparable)

1. Hard as stone
   • 1998, Oliver Stone, A Child's Night Dream‎, →ISBN, page 51:

     To stare into his cold stonehard heart.

   • 2013, D. de Moulin, A short history of breast cancer, page 12:

     The second patient of Cosmas and Damian was suffering from a stone-hard tumour in the breast, that had given rise to a contraction around the nipple.

• hardstone