Source : Webster's Revised Unabridged Dictionary (1913)

Trustworthy \Trust"wor`thy\, a.
   Worthy of trust or confidence; trusty. --
   {Trust"wor`thi*ness}, n.

Source : WordNet®

trustworthiness
     n : the trait of deserving trust and confidence [syn: {trustiness}]
         [ant: {untrustworthiness}, {untrustworthiness}]