mus·ter 
(mŭstər)
(mŭstər)v. mus·tered, mus·ter·ing, mus·ters
v.tr.
1. To call (troops) together, as for inspection.
2. To cause to come together; gather: Bring all the volunteers you can muster.
3. To bring into existence or readiness; summon up: mustering up her strength for the ordeal. See Synonyms at call.
v.intr.
To assemble or gather: mustering for inspection.
n.
Phrasal Verbs: 1.
a. A gathering, especially of troops, for service, inspection, review, or roll call.
b. The persons assembled for such a gathering.
2. A muster roll.
3. A gathering or collection: a muster of business leaders at a luncheon.
4. A flock of peacocks.
muster in
To enlist or be enlisted in military service: She mustered in at the age of 18.
muster out
Idiom: To discharge or be discharged from military service: He was mustered out when the war ended.
pass muster
To be judged as acceptable.
[Middle English mustren, from Old French moustrer, from Latin mōnstrāre, to show, from mōnstrum, sign, portent, from monēre, to warn; see men-1 in the Appendix of Indo-European roots.]