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):

mealy-mouthed
    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]

Moby Thesaurus II by Grady Ward, 1.0:

86 Moby Thesaurus words for "mealymouthed":
   Pecksniffian, Tartuffian, Tartuffish, abject, adulatory, affected,
   backscratching, beggarly, bland, blandishing, blarneying,
   bootlicking, buttery, cajoling, canting, casuistic, complimentary,
   courtierly, courtly, cowering, crawling, cringing, crouching,
   dishonest, disingenuous, empty, fair-spoken, false, fawning,
   fine-spoken, flattering, footlicking, fulsome, goody, goody-goody,
   groveling, gushing, hangdog, holier-than-thou, hollow,
   honey-mouthed, honey-tongued, honeyed, hypocritic, hypocritical,
   ingratiating, insincere, insinuating, jesuitic, obeisant,
   obsequious, oily, oily-tongued, on bended knee, parasitic,
   pharisaic, pharisean, pietistic, pious, prostrate, sanctified,
   sanctimonious, self-righteous, simon-pure, slimy, slobbery, smarmy,
   smooth, smooth-spoken, smooth-tongued, sniveling, soapy,
   soft-soaping, sponging, sycophantic, timeserving, toadeating,
   toadying, toadyish, tongue in cheek, truckling, uncandid, unctuous,
   unfrank, unserious, wheedling



Moby Thesaurus II by Grady Ward, 1.0:

19 Moby Thesaurus words for "mealy-mouthed":
   ambiguous, artful, circumlocutory, deceitful, equivocal,
   equivocating, euphemistic, hesitant, hypocritical, indirect,
   mincing, oily, periphrastic, reluctant, reticent, roundabout,
   slick, unctuous, vague