Source : Webster's Revised Unabridged Dictionary (1913)

Responsible \Re*spon"si*ble\ (r?*sp?n"s?*b'l), a. [Cf. F.
   responsable. See {Respond}.]
   1. Liable to respond; likely to be called upon to answer;
      accountable; answerable; amenable; as, a guardian is
      responsible to the court for his conduct in the office.

   2. Able to respond or answer for one's conduct and
      obligations; trustworthy, financially or otherwise; as, to
      have a responsible man for surety.

   3. Involving responsibility; involving a degree of
      accountability on the part of the person concerned; as, a
      responsible office.

   Syn: Accountable; answerable; amenable. --
        {Re*spon"si*ble*ness}, n. -- {Re*spon"si*bly}, adv.

Source : WordNet®

responsibleness
     n : a form of trustworthiness; the trait of being answerable to
         someone for something or being responsible for one's
         conduct; "he holds a position of great responsibility"
         [syn: {responsibility}] [ant: {irresponsibility}, {irresponsibility}]