noun

• (countable) A splinter, fragment or chip, especially of stone.
  "My father knew Bert Le Feuvre, the foreman of Griffith's yard, and there was a little heap of spawls waiting ready every night in summer after school for me to crack."
• (uncountable, especially concerning ferroconcrete structures or metal objects) A process of weathering, aging, or other wear that involves the crumbling of the substrate.
  "The failure of this bearing involved spall under high load."

verb

• (ambitransitive) To break into fragments or small pieces.
  "Cobbed Ore is the ſpalled which is broke out of the ſolid large ſtones with ſledges"
• (especially of ferroconcrete structures or metal objects) To undergo weathering, aging, or other wear that involves the crumbling of the substrate.
  "When the bearing race spalled under high load, it led to the failure of the bearing."
• (transitive) To reduce, as irregular blocks of stone, to an approximately level surface by hammering.

noun

• (obsolete, rare) The shoulder.
  "Their mightie ſtrokes their haberieons diſmayld, / And naked made each others manly ſpalles; […]"