Dornick is cited in the Oxford English Dictionary as a dialectical US term originating in the mid-19th century, meaning `pebble, stone or small boulder.` The OED suggests a derivation from Irish `dornog` (small stone). The Cassell Dictionary of Slang notes it was also used to mean `coin.` `Hard as dornick` was a colloquial way of affirming...
stout linen
• (n.) Alt. of Dornock
Dornick is a kind of stout figured linen fabric used for table-cloths, and generally chequered.
a stout linen cloth, esp. one of a damask linen.