The Collaborative International Dictionary of English v.0.48:

Irrepleviable \Ir`re*plev"i*a*ble\, Irreplevisable
\Ir`re*plev"i*sa*ble\, a. (Law)
   Not capable of being replevied.
   [1913 Webster]

Bouvier's Law Dictionary, Revised 6th Ed (1856):

IRREPLEVISABLE, practice. This term is applied to those things which cannot
legally be replevied. For example, in Pennsylvania no goods seized in
execution or for taxes, can be replevied.