Definition of tough-mindedness:
(adj) :
(of a material) Strong and resilient; sturdy.
(adj) :
(of food) Difficult to cut or chew.
(adj) :
(of a person or animal) Rugged or physically hardy.
(adj) :
(of a person) Stubborn or persistent; capable of stubbornness or persistence.
(adj) :
(of weather, etc.) Harsh or severe.
(adj) :
(of questions, etc.) Difficult or demanding.