What's the meaning of the phrase 'Bone dry'?
What's the origin of the phrase 'Bone dry'?
'Bone dry' clearly derives from an allusion to the dryness of bone after being left in the sun. The equivalent phrase 'as dry as a bone' give testament to that, as virtually all of the 'as X as Y' similes point to a well-known property (that is, X) of some person or thing (that is, Y).
The earliest known citation of 'bone dry' is in itself a definition of the phrase in just those terms. It comes in a glossary written by the clergyman Robert Forby in 1830. I've included the full title of Forby's work, as it's always a pleasure to see a title that is longer than the citation taken from it - The Vocabulary Of East Anglia; An Attempt To Record The Vulgar Tongue Of The Twin Sister Counties, Norfolk And Suffolk, As It Existed And Still Exists; With Proof Of Its Antiquity From Etymology And Authority:
"BONE-DRY, adj. perfectly dry; as dry as a bone long bleached in the weather."