What does "count out" mean?

Declare a boxer (or other contestant) to have lost, as in Paul was counted out in the first round. This term alludes to count in the sense of “ten seconds,” the time allowed for a boxer to rise after being knocked down (if he does not rise in time, he is “out”). The earliest recorded use of the term was for a cockfight in 1808; its use for boxing came about a century later. Also see down for the count.

Exclude, leave out of consideration, as in As for skiing this winter, you'll have to count me out. [Colloquial; mid-1800s] Also see count in.

Apportion; also, recalculate. For example, They counted out four pieces of music for each band member, or When Peggy got her change she counted out all the pennies. [Mid-1800s]