Source : Webster's Revised Unabridged Dictionary (1913)

Sloth \Sloth\, n. [OE. slouthe, sleuthe, AS. sl?w?, fr. sl[=a]w
   slow. See {Slow}.]
   1. Slowness; tardiness.

            These cardinals trifle with me; I abhor This
            dilatory sloth and tricks of Rome.    --Shak.

   2. Disinclination to action or labor; sluggishness; laziness;
      idleness.

            [They] change their course to pleasure, ease, and
            sloth.                                --Milton.

            Sloth, like rust, consumes faster than labor wears.
                                                  --Franklin.

   3. (Zo["o]l.) Any one of several species of arboreal
      edentates constituting the family {Bradypodid[ae]}, and
      the suborder Tardigrada. They have long exserted limbs and
      long prehensile claws. Both jaws are furnished with teeth
      (see Illust. of {Edentata}), and the ears and tail are
      rudimentary. They inhabit South and Central America and
      Mexico.

   Note: The three-toed sloths belong to the genera {Bradypus}
         and {Arctopithecus}, of which several species have been
         described. They have three toes on each foot. The
         best-known species are collared sloth ({Bradypus
         tridactylus}), and the ai ({Arctopitheus ai}). The
         two-toed sloths, consisting the genus {Cholopus}, have
         two toes on each fore foot and three on each hind foot.
         The best-known is the unau ({Cholopus didactylus}) of
         South America. See {Unau}. Another species ({C.
         Hoffmanni}) inhabits Central America. Various large
         extinct terrestrial edentates, such as Megatherium and
         Mylodon, are often called sloths.

   {Australian, or Native} {sloth} (Zo["o]l.), the koala.

   {Sloth animalcule} (Zo["o]l.), a tardigrade.

   {Sloth bear} (Zo["o]l.), a black or brown long-haired bear
      ({Melursus ursinus, or labiatus}), native of India and
      Ceylon; -- called also {aswail}, {labiated bear}, and
      {jungle bear}. It is easily tamed and can be taught many
      tricks.

   {Sloth monkey} (Zo["o]l.), a loris.

Sloth \Sloth\, v. i.
   To be idle. [Obs.] --Gower.

Source : WordNet®

sloth
     n 1: a disinclination to work or exert yourself [syn: {slothfulness}]
     2: any of several slow-moving arboreal mammals of South America
        and Central America; they hang from branches back downward
        and feed on leaves and fruits [syn: {tree sloth}]
     3: apathy and inactivity in the practice of virtue (personified
        as one of the deadly sins) [syn: {laziness}, {acedia}]