bite one's lip

bite one's lip (third-person singular simple present bites one's lip, present participle biting one's lip, simple past bit one's lip, past participle bitten one's lip)

(idiomatic) To forcibly prevent oneself from speaking, especially in order to avoid saying something inappropriate or likely to cause a dispute.
- 1822, [Walter Scott], chapter XIII, in Peveril of the Peak. […], volume IV, Edinburgh: […] Archibald Constable and Co.; London: Hurst, Robinson, and Co., →OCLC, page 304:
  Buckingham bit his lip, for he saw the introduction of Lady Derby was likely to confuse and embroil every preparation which he had arranged for his defence; […]
- 1922, F[rancis] Scott Fitzgerald, “(please specify the page)”, in Tales of the Jazz Age, New York, N.Y.: Charles Scribner’s Sons, →OCLC:
  He broke off and bit his lip, feeling that he had better subdue the rising anger in his voice.

English