As an adjective tough

is strong and resilient; sturdy.

As an interjection tough

is (slang) (used to indicate lack of sympathy).

As a noun tough

is a person who obtains things by force; a thug or bully.

As a verb tough

is to endure.

As a letter x is

the twenty-fourth letter of the.

As a symbol x is

voiceless velar fricative.

As nouns the difference between terms and lermontovite

is that terms is while lermontovite is (mineralogy) an orthorhombic-dipyramidal gray green mineral containing hydrogen, oxygen, phosphorus, and uranium.

As nouns the difference between terms and lehnerite

is that terms is while lehnerite is (mineralogy) a monoclinic-prismatic mineral containing hydrogen, manganese, oxygen, phosphorus, and uranium.

As nouns the difference between terms and lesukite

is that terms is while lesukite is (mineralogy) an isometric-hexoctahedral mineral containing aluminum, chlorine, hydrogen, and oxygen.

As nouns the difference between terms and hydroxycancrinite

is that terms is while hydroxycancrinite is (mineral) a hexagonal-pyramidal mineral containing aluminum, hydrogen, oxygen, silicon, and sodium.

As nouns the difference between terms and hydroscarbroite

is that terms is while hydroscarbroite is (mineral) a triclinic white mineral containing aluminum, carbon, hydrogen, and oxygen.

As nouns the difference between terms and hydrohetaerolite

is that terms is while hydrohetaerolite is (mineral) a tetragonal-ditetragonal dipyramidal mineral containing hydrogen, manganese, oxygen, and zinc.

As nouns the difference between terms and lenoblite

is that terms is while lenoblite is (mineralogy) an orthorhombic-disphenoidal mineral containing hydrogen, oxygen, and vanadium.

As nouns the difference between terms and hydrohalite

is that terms is while hydrohalite is (mineral) a monoclinic-prismatic mineral containing chlorine, hydrogen, oxygen, and sodium.

As nouns the difference between terms and magnetoplumbite

is that terms is while magnetoplumbite is (mineralogy) a hexagonal-dihexagonal dipyramidal gray mineral containing aluminum, calcium, iron, lead, manganese, oxygen, and titanium.