The Collaborative International Dictionary of English v.0.48:

cytosol \cy"to*sol\ (s[imac]"t[-o]*s[add]l or
   s[imac]"t[-o]*s[o^]l), n. (Biology)
   The soluble components of the fluid matter enclosed within
   the cellular membrane; the portion of the cytoplasm which
   remains after removal of particulate components.
   [PJC]

WordNet (r) 3.0 (2006):

cytosol
    n 1: the aqueous part of the cytoplasm within which various
         particles and organelles are suspended