Related Clues:

• Really get into
• Jab
• Yawner
• Use a mattock
• With 52-Across, what treasure hunters do
• Hardly the life of the party
• Do some research
• Hollow out
• Sarcastic comment
• Dullard
• Be into
• Unkind remark
• Tiresome one
• Yawn-inducing speaker
• "Understand?"