Difficult or demanding.
Harsh or severe.
Stubborn or persistent; capable of stubbornness or persistence.
Strong and resilient; sturdy.
Undergoing plastic deformation before breaking.
Difficult to cut or chew.
Rugged or physically hardy.
Rowdy or rough.
A person who obtains things by force; a thug or bully.
Used to indicate lack of sympathy
To endure.
To toughen.
Of, relating to, or being the simplest possible case.
Commonplace, ordinary.
Pertaining to the trivium.
Ignorable; of little significance or value.
Relating to or designating the name of a species; specific as opposed to generic.
Self-evident.
Concerned with or involving trivia.
Indistinguishable in case of truth or falsity.