Source : Webster's Revised Unabridged Dictionary (1913)

Zany \Za"ny\, v. t.
   To mimic. [Obs.]

         Your part is acted; give me leave at distance To zany
         it.                                      --Massinger.

Zany \Za"ny\, n.; pl. {Zanies}. [It. zanni a buffoon,
   merry-andrew, orig. same as Giovanni John, i. e., merry John,
   L. Ioannes, Gr. ?, Heb. Y[=o]kh[=a]n[=a]n, prop., the Lord
   graciously gave: cf. F. zani, fr. the Italian. Cf.
   {Jenneting}.]
   A merry-andrew; a buffoon.

         Then write that I may follow, and so be Thy echo, thy
         debtor, thy foil, thy zany.              --Donne.

         Preacher at once, and zany of thy age.   --Pope.

Source : WordNet®

zany
     adj 1: pungent adjectives of disesteem; "gave me a cockamamie
            reason for not going"; "wore a goofy hat"; "a silly
            idea"; "some wacky plan for selling more books" [syn:
            {cockamamie}, {cockamamy}, {goofy}, {sappy}, {silly},
            {wacky}, {whacky}, {unreasonable}]
     2: like a clown; "a buffoonish walk"; "a clownish face"; "a
        zany sense of humor" [syn: {buffoonish}, {clownish}, {clowlike}]
     n 1: a buffoon in one of the old comedies; imitates others for
          ludicrous effect
     2: a man who is a stupid incompetent fool [syn: {fathead}, {goof},
         {goofball}, {bozo}, {jackass}, {goose}, {cuckoo}, {twat}]
     [also: {zaniest}, {zanier}]