Related Clues:

• 'I'm game if you are!'
• Tennis umpire's calls
• Restricts? No, U-turn
• 'We should do it!'
• Agreeable answer to an invitation
• Some bad serves
• Start of a suggestion
• Confesses to trashing stadium after United's lost
• ''I'm up for it!''
• Badminton do-overs
• '___ party!'
• Calls to reserve?
• Its apostrophe replaces a "u"
• ... announcements about American university's grants
• "I'm up for it!"