Source : Webster's Revised Unabridged Dictionary (1913)

Sappy \Sap"py\, a. [Compar. {Sappier}; superl. {Sappiest}.]
   [From 1st {Sap}.]
   1. Abounding with sap; full of sap; juicy; succulent.

   2. Hence, young, not firm; weak, feeble.

            When he had passed this weak and sappy age.
                                                  --Hayward.

   3. Weak in intellect. [Low]

   4. (Bot.) Abounding in sap; resembling, or consisting largely
      of, sapwood.

Source : WordNet®

sappy
     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}, {silly}, {wacky},
            {whacky}, {zany}, {unreasonable}]
     2: abounding in sap; "sappy maple trees"; "sappy kindling wood"
     [also: {sappiest}, {sappier}]

sappiest
     See {sappy}