Source : Webster's Revised Unabridged Dictionary (1913)

Infect \In*fect"\, a. [L. infectus: cf. F. infect. See {Infect},
   v. t.]
   Infected. Cf. {Enfect}. [Obs.] --Shak.

Infect \In*fect"\, v. t. [imp. & p. p. {Infected}; p. pr. & vb.
   n. {Infecting}.] [L. infectus, p. p. of inficere to put or
   dip into, to stain, infect; pref. in- in + facere to make;
   cf. F. infecter. See {Fact}.]
   1. To taint with morbid matter or any pestilential or noxious
      substance or effluvium by which disease is produced; as,
      to infect a lancet; to infect an apartment.

   2. To affect with infectious disease; to communicate
      infection to; as, infected with the plague.

            Them that were left alive being infected with this
            disease.                              --Sir T.
                                                  North.

   3. To communicate to or affect with, as qualities or
      emotions, esp. bad qualities; to corrupt; to contaminate;
      to taint by the communication of anything noxious or
      pernicious. --Cowper.

            Infected Ston's daughters with like heat. --Milton.

   4. (Law) To contaminate with illegality or to expose to
      penalty.

   Syn: To poison; vitiate; pollute; defile.

Source : WordNet®

infect
     v 1: communicate a disease to; "Your children have infected you
          with this head cold"
     2: contaminate with a disease or microorganism [syn: {taint}]
        [ant: {disinfect}]
     3: contaminate with ideas or an ideology; "society was infected
        by racism"
     4: affect in a contagious way; "His laughter infects everyone
        who is in the same room"