tough
(of a material) {{U|strong}} and resilient; sturdy.
(of food) {{U|difficult}} to cut or chew.
(of a person) {{U|stubborn}} or persistent; capable of stubbornness or persistence.
(of weather, etc.) Harsh or severe.
{{U|rowdy}} or rough.
(of questions, etc.) {{U|difficult}} or demanding.
(material science) Undergoing plastic deformation before breaking.
{{U|strict}}, not lenient.
(slang) {{non-gloss|Used to indicate lack of sympathy}}
A person who obtains things by force; a thug or bully.
To endure.
To toughen.