Possible Clues:

• "Eat crow" or "talk turkey"
• Language used by a people or group
• Ten thousand I had, in a manner of speaking
• Jargon
• Nonliteral phrase
• Group of words in which the meaning may not be obvious
• Quirky phrase
• Love trapped by one obscure colloquialism
• Linguistic quirk
• Hit the sack, e.g.