Source : Webster's Revised Unabridged Dictionary (1913)

Chorisis \Cho"ri*sis\, n. [NL., fr. Gr. ? separation.] (Bot.)
   The separation of a leaf or floral organ into two more parts.

   Note: In collateral chorisis the parts are side by side. --
         In parallel or median chorisis they are one in front of
         another.