Source : Webster's Revised Unabridged Dictionary (1913)

Swear \Swear\, v. i. [imp. {Swore}, formerly {Sware}; p. p.
   {Sworn}; p. pr. & vb. n. {Swearing}.] [OE. swerien, AS.
   swerian; akin to D. zweren, OS. swerian, OHG. swerien, G.
   schw["o]ren, Icel. sverja, Sw. sv["a]rja, Dan. sv[ae]rge,
   Icel. & Sw. svara to answer, Dan. svare, Dan. & Sw. svar an
   answer, Goth. swaran to swear, and perhaps to E. swarm.
   [root]177. Cf. {Answer}.]
   1. To affirm or utter a solemn declaration, with an appeal to
      God for the truth of what is affirmed; to make a promise,
      threat, or resolve on oath; also, to affirm solemnly by
      some sacred object, or one regarded as sacred, as the
      Bible, the Koran, etc.

            Ye shall swear by my name falsely.    --Lev. xix.
                                                  12.

            I swear by all the Roman gods.        --Shak.

   2. (Law) To give evidence on oath; as, to swear to the truth
      of a statement; he swore against the prisoner.

   3. To make an appeal to God in an irreverant manner; to use
      the name of God or sacred things profanely; to call upon
      God in imprecation; to curse.

            [I] swore little; diced not above seven times a
            week.                                 --Shak.

   {To swear by}, to place great confidence in a person or
      thing; to trust implicitly as an authority. ``I simply
      meant to ask if you are one of those who swear by Lord
      Verulam.'' --Miss Edgeworth.

   {To swear off}, to make a solemn vow, or a serious
      resolution, to abstain from something; as, to swear off
      smoking. [Slang]

Swore \Swore\,
   imp. of {Swear}.

Source : WordNet®

swear
     v 1: utter obscenities or profanities; "The drunken men were
          cursing loudly in the street" [syn: {curse}, {cuss}, {blaspheme},
           {imprecate}]
     2: to declare or affirm solemnly and formally as true; "Before
        God I swear I am innocent" [syn: {affirm}, {verify}, {assert},
         {avow}, {aver}, {swan}]
     3: promise solemnly; take an oath
     4: make a deposition; declare under oath [syn: {depose}, {depone}]
     5: have confidence or faith in; "We can trust in God"; "Rely on
        your friends"; "bank on your good education"; "I swear by
        my grandmother's recipes" [syn: {trust}, {rely}, {bank}]
        [ant: {distrust}, {distrust}]
     [also: {sworn}, {swore}]

swore
     See {swear}