The Collaborative International Dictionary of English v.0.48:

Indeliberate \In`de*lib"er*ate\, a. [L. indeliberatus. See In-
   not, and Deliberate.]
   Done without deliberation; unpremeditated. [Obs.] --
   In`de*lib"er*ate*ly, adv. [Obs.]
   [1913 Webster]