Related Clues:

• Olivier or John, e.g.
• How to address a lt. col.?
• Boot camp boss, informally
• Ma'am's mate
• See 109-Across
• Squad leader
• Polite word
• Private's boss
• Part of an address on an overseas ltr.
• Baronet's address
• McCartney title
• Title
• “Dear” letter recipient
• Address for the general
• G.I.'s mail drop