compulsory military service
"The government announced that all eligible men must report for duty immediately to fulfill their mandatory enlistment during wartime."
Gathering.
"The general managed to muster enough courage to face his fears after weeks of hesitation."
An assemblage or display; a gathering, collection of people or things.
Synonym of mustee
call to duty, military service, jury duty, etc.
"The general ordered all available troops to muster at the town square before dawn."
To show, exhibit.
"She managed to muster a small smile despite her exhaustion after the long hike."