The Collaborative International Dictionary of English v.0.48:

Mealy-mouthed \Meal"y-mouthed`\, a.
   Using soft words; not straightforward; plausible; affectedly
   or timidly delicate of speech; speaking deviously; unwilling
   to tell the truth in plain language. Opposite of frank or
   blunt. "Mealy-mouthed philanthropies." --Tennyson.
   [1913 Webster]

         She was a fool to be mealy-mouthed where nature speaks
         so plain.                                --L'Estrange.
   [1913 Webster] -- Meal"y-mouth`ness, n.
   [1913 Webster]

WordNet (r) 3.0 (2006):

mealymouthed
    adj 1: hesitant to state facts or opinions simply and directly
           as from e.g. timidity or hypocrisy; "a mealymouthed
           politician" [syn: mealymouthed, mealy-mouthed]