Related Clues:

• Try soldier and avoid bloomers
• Not be underdressed?
• Not cover one's butt?
• Order soldier to move unbriefed?
• A way to be underdressed
• Leave one's drawers in the drawer, say
• Debrief?
• Not wear boxers, say (In this clue's answer, note letters 5, 7 & 9)
• Not wear underwear