within a whisker of (something)
Very close to something. I swear the car came within a whisker of hitting the train, but stopped at the last second. I came within a whisker of winning that race, but I guess I'll have to settle for second place.
within a whisker of something
If something is within a whisker of a particular amount, it is almost that amount. The price of gold is now within a whisker of $330 an ounce.
within a whisker of
extremely close or near to doing, achieving, or suffering something. informal