Related Clues:

• Mining passage
• Sounds like the entire pig that's the drill!
• That's the drill, one got down to making it
• By the sound of it, make all present yawn - that's the drill
• (A) deep drilling for oil, water
• Deep excavation to find water
• Something drilled to find water/oil
• An excavation to reach groundwater
• Passage made by a drill, for exploratory purposes
• It's made to locate water or oil
• What’s drilled to reach water or oil
• Well, look, hero is back in bed, getting end away