to the backbone

prep_phrase

to the backbone

prep_phrase

1

Idiomatic Through and through; thoroughly; entirely.

staunch to the backbone1834, Edward Bulwer-Lytton, The Last Days of Pompeii:
Sir Culling was an extreme Low Churchman, an Exeter Hallite to the backbone, and the head and front of the Platitudinarian Party.1894, Richard William Murray, South African Reminiscences, page 138:

1 more example

In temperament he was Dutch to the backbone — at least as we imagine Dutch.1907, Alfred Thayer Mahan, From Sail to Steam: Reflections of Naval Life:

Entry derived from the Wiktionary, under licence CC BY-SA 4.0 — list of authors.