to make it easier for something to happen.

An aid programme was established to oil the wheels of economic reform in the region. (usually + of)

• for anything in the world
• for a price
• for a song
• for better or for worse
• for better or worse
• forbidden fruit
• force hand
• force of habit
• for certain
• force someone's hand
• force to be reckoned with
• for Christ's sake
• for crying out loud
• For crying out loud!
• foregone conclusion
• forelock-tugging
• forewarned is forearmed
• Forewarned is forearmed.
• forget about
• forget about it
• forget about something
• forget it
• forgive and forget
• for God's sake
• for good