What is an academic and formal way to define variables? I'm currently writing my IB Extended Essay in physics. I wonder how I can define variables in a formal way. I originally used a triple bar (e.g. "F≡buoyant force"). However, I'm not sure if this is formal or even correct. What is an academic and formal way to define variables?
The academic way to define variables is to simply describe them in the text. For instance,


  F = ma,
  where F is the force acting on the point mass m and a is the acceleration.


In fact, we want scientific texts to be readable, and not overburdened with unnecessary and obscure notations. Symbols have their role, but don't overuse them. Even more, a symbol like the triple bar has different technical meanings in different disciplines and using it in that way may just generate confusion.