The Meta-game: What is it and where did it come from?

I spoke to one of the lecturers I work with and tried to explain what a meta-game is to him once.

“It’s an abstraction of what ways of playing are popular, a sort of game within a game about what ways of playing are being used and how to best play against them. An ever evolving state of play where what’s popular is defined by what’s good against what was popular in the recent past”

He was having none of it, to his mind this was neither meta, nor a game.