screw up (your) courage

to force yourself to be brave.

Jimmy screwed up his courage and gave Lisa a heart-shaped box of chocolates on Valentine's Day.

• for naught
• for nothing
• for old times' sake
• for one thing
• for openers
• for own sake
• for part
• for Pete's sake
• for quids
• for real
• for short
• for someone's part
• for some reason
• for some reason or other
• for something's own sake
• for starters
• for sure
• for that matter
• for the asking
• for the best
• for the better
• for the birds
• for the heck of it
• for the hell of it
• for the life of