Definition
To gather or bring together strength, courage, or resources that you need to do something difficult.
Example
She mustered all her courage and spoke up.
Show translation
She gathered all her courage and spoke up.
Etymology
From Old French *moustrer* ("to show, display"), from Latin *monstrare* ("to show"), related to *monstrum* ("portent, sign"). In medieval military use, a "muster" was a formal inspection or assembly of troops — soldiers were literally shown or displayed for counting. By the 16th century, the verb broadened to mean assembling any resource, including inner qualities like bravery.
Cultural note
The phrase **"pass muster"** — meaning to meet an acceptable standard — comes directly from this military inspection sense. If a soldier passed the muster roll call, they were fit for duty. Today you might hear "that excuse barely passes muster" in everyday conversation, often with a hint of scepticism. It's used across all English-speaking regions with no significant regional variation.