Source : Webster's Revised Unabridged Dictionary (1913)

Shelter \Shel"ter\, v. i.
   To take shelter.

         There oft the Indian herdsman, shunning heat, Shelters
         in cool.                                 --Milton.

Shelter \Shel"ter\, n. [Cf. OE. scheltrun, shiltroun,
   schelltrome, scheldtrome, a guard, squadron, AS. scildtruma a
   troop of men with shields; scild shield + truma a band of
   men. See {Shield}, n.]
   1. That which covers or defends from injury or annoyance; a
      protection; a screen.

            The sick and weak the healing plant shall aid, From
            storms a shelter, and from heat a shade. --Pope.

   2. One who protects; a guardian; a defender.

            Thou [God] hast been a shelter for me. --Ps. lxi. 3.

   3. The state of being covered and protected; protection;
      security.

            Who into shelter takes their tender bloom. --Young.

   {Shelter tent},a small tent made of pieces of cotton duck
      arranged to button together. In field service the soldiers
      carry the pieces.

   Syn: Asylum; refuge; retreat; covert; sanctuary; protection;
        defense; security.

Shelter \Shel"ter\, v. t. [imp. & p. p. {Sheltered}; p. pr. &
   vb. n. {Sheltering}.]
   1. To be a shelter for; to provide with a shelter; to cover
      from injury or annoyance; to shield; to protect.

            Those ruins sheltered once his sacred head.
                                                  --Dryden.

            You have no convents . . . in which such persons may
            be received and sheltered.            --Southey.

   2. To screen or cover from notice; to disguise.

            In vain I strove to cheek my growing flame, Or
            shelter passion under friendship's name. --Prior.

   3. To betake to cover, or to a safe place; -- used
      reflexively.

            They sheltered themselves under a rock. --Abp.
                                                  Abbot.

Source : WordNet®

shelter
     n 1: a structure that provides privacy and protection from danger
     2: protective covering that provides protection from the
        weather
     3: the condition of being protected; "they were huddled
        together for protection"; "he enjoyed a sense of peace and
        protection in his new home" [syn: {protection}]
     4: a way of organizing business to reduce the taxes it must pay
        on current earnings [syn: {tax shelter}]
     5: temporary housing for homeless or displaced persons

shelter
     v 1: provide shelter for; "After the earthquake, the government
          could not provide shelter for the thousands of homeless
          people"
     2: invest (money) so that it is not taxable