1862. Guardian, 16 April, 1. The fort which can mount the hugest ordnance, and can be so constructed as not to be crackable.
1873. Miss Broughton, Nancy, I. 221. Most of them of a brittle crackable nature.
b. as sb. (in pl.) Things that can be cracked. (nonce-use, after eatables, etc.).
1841. J. T. Hewlett, Parish Clerk, I. 100. Fond o breaking crackables.
Hence Crackability, quality of being crackable.
1810. W. Taylor, in Monthly Mag., 344. The crackability, which is here made the characteristic of this sort of nut.