The Collaborative International Dictionary of English v.0.48:

Gummy \Gum"my\, a. [Compar. Gummer (?); superl. Gummirst.]
   Consisting of gum; viscous; adhesive; producing or containing
   gum; covered with gum or a substance resembling gum.
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         Kindles the gummy bark of fir or pine.   --Milton.
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         Then rubs his gummy eyes.                --Dryden.
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   Gummy tumor (Med.), a gumma.
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WordNet (r) 3.0 (2006):

gummy
    adj 1: having the sticky properties of an adhesive [syn:
           gluey, glutinous, gummy, mucilaginous, pasty,
           sticky, viscid, viscous]
    2: covered with adhesive gum [syn: gummed, gummy]