Source : Webster's Revised Unabridged Dictionary (1913)

Pet \Pet\, v. t. [imp. & p. p. {Petted}; p. pr. & vb. n.
   {Petting}.]
   To treat as a pet; to fondle; to indulge; as, she was petted
   and spoiled.

Source : WordNet®

pet
     adj : preferred above all others and treated with partiality; "the
           favored child" [syn: {favored}, {favorite(a)}, {favourite(a)},
            {preferred}]
     [also: {petting}, {petted}]

pet
     n 1: a domesticated animal kept for companionship or amusement
     2: a special loved one [syn: {darling}, {favorite}, {favourite},
         {dearie}, {deary}, {ducky}]
     3: a fit of petulance or sulkiness (especially at what is felt
        to be a slight)
     4: using a computerized radiographic technique to examine the
        metabolic activity in various tissues (especially in the
        brain) [syn: {positron emission tomography}]
     [also: {petting}, {petted}]

petting
     n : affectionate play (or foreplay without contact with the
         genital organs) [syn: {caressing}, {cuddling}, {fondling},
          {hugging}, {kissing}, {necking}, {smooching}, {snuggling}]

pet
     v 1: stroke or caress gently; "pet the lamb"
     2: stroke or caress in an erotic manner, as during lovemaking
     [also: {petting}, {petted}]

petting
     See {pet}