The Collaborative International Dictionary of English v.0.48:

Unassured \Un`as*sured"\, a.
   1. Not assured; not bold or confident.
      [1913 Webster]

   2. Not to be trusted. [Obs.] --Spenser.
      [1913 Webster]

   3. Not insured against loss; as, unassured goods.
      [1913 Webster]

WordNet (r) 3.0 (2006):

unassured
    adj 1: lacking boldness or confidence

Moby Thesaurus II by Grady Ward, 1.0:

19 Moby Thesaurus words for "unassured":
   backward, bashful, diffident, insecure, modest, rabbity, retiring,
   self-effacing, shy, timid, unassertive, unconfident, undependable,
   unreliable, unselfassured, unselfconfident, unselfreliant, unsure,
   untrustworthy