[mas-ter-uh
t-ahrmz, mah-ster-] 
| 1. | an officer of a fraternal organization, veterans' society, or the like, empowered to maintain order, exclude unauthorized persons, etc. |
| 2. | Navy. a petty officer who has various duties, such as keeping order on the ship, taking charge of prisoners, etc. |
| mas·ter-at-arms (mās'tər-ət-ärmz') n. pl. mas·ters-at-arms (mās'tərz-) A petty officer assigned to maintain order. |