The Collaborative International Dictionary of English v.0.48:

Suberization \Su`ber*i*za"tion\, n. (Bot.)
   Conversion of the cell walls into cork tissue by development
   of suberin; -- commonly taking place in exposed tissues, as
   when a callus forms over a wound. Suberized cell walls are
   impervious to water.
   [Webster 1913 Suppl.]