Source : Webster's Revised Unabridged Dictionary (1913)

Perchance \Per*chance"\, adv. [F. par by (L. per) + chance. See
   {Par}, and {Chance}.]
   By chance; perhaps; peradventure.

Source : WordNet®

perchance
     adv 1: through chance, "To sleep, perchance to dream.." [syn: {by
            chance}]
     2: by chance; "perhaps she will call tomorrow"; "we may
        possibly run into them at the concert"; "it may
        peradventure be thought that there never was such a time"
        [syn: {possibly}, {perhaps}, {maybe}, {mayhap}, {peradventure}]