Related Clues:

• White knight, stereotypically
• Luncheonette letters
• Bagel extra
• Layered sandwich
• Johnny-on-the-spot, perhaps
• Sandwich with mayo
• Han or Luke, e.g.
• Sandwich often served with mayo
• Sonar user
• Subway purchase, perhaps
• Warship
• Stand-in, for short
• Sandwich shop order
• NASA fuel element
• Super sandwich