The Collaborative International Dictionary of English v.0.48:

Sniveler \Sniv"el*er\, n. [Written also sniveller.]
   One who snivels, esp. one who snivels habitually.
   [1913 Webster]

WordNet (r) 3.0 (2006):

sniveler
    n 1: a person who breathes audibly through a congested nose
         [syn: sniffler, sniveler]

Moby Thesaurus II by Grady Ward, 1.0:

25 Moby Thesaurus words for "sniveler":
   Holy Willie, Joseph Surface, Mawworm, Pecksniff, Pharisee,
   Tartuffe, affecter, canter, canting hypocrite, dissembler,
   dissimulator, formalist, hypocrite, lip server, lip worshiper,
   pharisee, pietist, pious fraud, poser, ranter, religionist,
   religious hypocrite, snuffler, spiritual humbug,
   whited sepulcher