In my experience it is very subjective and generally contextual what either side of that equation means.
The term meritocracy has often been by people who have a very clear view on what contribution and reward mean and they typically assume a closed and fair system where everyone already agreed on the meaning of those terms and on the rules on how to evaluate those things on a case by case basis.
To be honest I'm just not sure whether it is a useful term at all outside of games, sports and other controlled systems with predefined and agreed upon rules.
The term meritocracy has often been by people who have a very clear view on what contribution and reward mean and they typically assume a closed and fair system where everyone already agreed on the meaning of those terms and on the rules on how to evaluate those things on a case by case basis.
To be honest I'm just not sure whether it is a useful term at all outside of games, sports and other controlled systems with predefined and agreed upon rules.