a bone of contention: something which people argue and disagree over.Examples: Medicaid costs have long been a bone of contention between counties and the state. How climate change will affect hurricanes has long been a bone of contention.

to tire out: to make very weary due to difficult conditions or hard effort (also:to wear out) Examples of TIRE OUT We need to tire out our puppy every night, or he’ll be so energetic we won’t be able to sleep. The first time we attended the spin class, we were the first to tire…

to come across: to meet or find unexpectedly (also: to run across); to be perceived or judged as (also: to come off) Examples of TO COME ACROSS A woman walking her dog came across a butchered body left on a pile of branches. I came across this story out of Georgia on a National Park…

to hold off: to delay, or to be delayed, in occurring Examples of TO HOLD OFF They’re snapping pictures of the new open-air ballpark and hoping the rain holds off. The judge agreed to hold off making a decision until new evidence could be introduced into court.

to burn out: to stop functioning because of overuse; to make tired from toomuck work Examples of TO BURN OUT Nissan says the clutch has burned out after just 1,290 miles and my driving is to blame. The housing market has burned out like a spent comet.

on purpose: for a reason, deliberately Examples of ON PURPOSE “So you’re telling me that you lost the game on purpose?” the commissioner asked the baseball player who was accused of taking a bribe. I tried to explain that the boy didn’t break the window on purpose, so his parents wouldn’t be mad at him.