Related Clues:

• Makes keen
• Makes sharper
• Sacks or cans
• Sets afire
• Sparks
• Builds a fire under
• Forest worries
• Inspires, with ''up''
• Conflagrations
• Sharpens, as an appetite
• Excites, with ''up''
• Lights a fire under
• Sets on fire
• Sets fire to
• Sing about a tie as one makes light of it