tomber sur un os

== French == === Etymology === Literally, “to come across a bone”. === Pronunciation === IPA(key): /tɔ̃.be syʁ œ̃.n‿ɔs/ === Verb === tomber sur un os to hit a snag, to find a fly in the ointment Synonym: tomber sur un bec ==== Conjugation ==== see tomber