Related Clues:

• Squeaking
• Squeaky, maybe
• Squeaky, perhaps
• Greased, as a 51 Across
• Like smooth-running engines
• Unlikely to rattle or squeak, say
• Applied grease to
• Oiled
• Greased up
• Squeaky clean son departs
• Applied oil to
• Squeaky, say
• Still squeaking
• Not lubricated
• No longer squeaking, perhaps