Related Clues:

• Dull fellow
• March around camp, e.g.
• Boot camp activity
• Barrel's inside diameter
• Gun barrel diameter
• Unwanted guest, maybe
• It can hold a little bit at a time
• Base exercise
• Tidal wave
• Put to sleep, so to speak
• Tedious fellow
• One causing ennui
• Drill holes
• Make weary by being dull
• Yawn producer, perhaps