What is the meaning of the word "counter"?

Definitions:

a computer register whose contents go through a regular series of states, usually states indicating consecutive integers noun
- I put a counter in my code to stop printing at ten lines.
a piece of leather forming the back of a shoe or boot noun
- a counter may be used to stiffen the material around the heel and to give support to the foot
in the opposite direction adverb
- run counter
to speak in response verb
- I countered with some very persuasive arguments.