Possible Clues:

• A late-night session in most bars where drink is served endlessly
• Guarantee, as a loan rate
• Post-closing time pub drinking session
• Shut up without means of escape
• Commit to, as picks for a March Madness bracket
• After closing time, an opportunity for a late drink on the canal up north
• Half of pubs and small hotels -- King's Head included -- will offer late session
• Guarantee, as a mortgage rate
• Finalize, as a Final Jeopardy! wager
• Fix, as an interest rate