put (someone) out of (their) misery

to stop someone worrying, usually by giving them information that they have been waiting for.

I thought I'd call her with the results today and put her out of her misery.

• if all else fails
• If at first you don't succeed.
• If at first you don't succeed, try, try, and try again.
• if can help it
• If can't stand the heat, get out of the kitchen.
• I feel it in my bones.
• if it ain't broke, don't fix it
• If it ain't broke, don't fix it.
• if it comes to the crunch
• if it weren't for
• if it weren't for someone
• if it weren't for something
• if knows what's good for
• if knows what's good for them
• If looks could kill...
• if memory serves
• If Mohammed will not go to the mountain, the mountain must come to Mohammed.
• if need be
• if push comes to shove
• if someone knows what's good for
• if someone knows what's good for them
• If someone thinks something, they've got another thing coming!
• If someone thinks something, they've got another think coming!
• If someone thinks, they've got another thing coming!
• If someone thinks, they've got another think coming!