From Wiktionary, the free dictionary
- IPA(key): /də kɛl bwa kɛl.k‿œ̃ s(ə) ʃof/
de quel bois quelqu’un se chauffe
- (informal) what someone is made of, what someone is capable of, someone's true mettle
- Synonym: ce qu’on a dans le ventre
- montrer de quel bois on se chauffe ― to show one's mettle
Chiefly used with the verbs montrer, voir and savoir.
