The phrase "brave face" suggests putting on a stoic expression to hide one's true emotions or fears. Some synonyms for this phrase include "putting up a front," "acting strong," "maintaining composure," and "presenting a facade." Other options might include "putting on a mask," "lying low," "pasting on a smile," "concealing one's feelings," and "displaying a stiff upper lip." Each of these terms shares the idea of concealing one's true feelings or vulnerabilities, and instead presenting a tough exterior to the world. Whether in the face of personal hardship or difficult circumstances, using these synonyms can help to convey the idea of resilience and determination.