The Collaborative International Dictionary of English v.0.48:

Replaceable \Re*place"a*ble\ (r?-pl?s"?-b'l), a.
   1. Capable or admitting of being put back into a place.
      [1913 Webster]

   2. Admitting of having its place supplied by a like thing or
      an equivalent; as, the lost book is replaceable.
      [1913 Webster]

   3. (Chem.) Capable of being replaced (by), or of being
      exchanged (for); as, the hydrogen of acids is replaceable
      by metals or by basic radicals.
      [1913 Webster]

WordNet (r) 3.0 (2006):

replaceable
    adj 1: capable of being replaced [ant: irreplaceable,
           unreplaceable]