The Collaborative International Dictionary of English v.0.48:

Strangler \Stran"gler\, n.
   One who, or that which, strangles. "The very strangler of
   their amity." --Shak.
   [1913 Webster]

WordNet (r) 3.0 (2006):

strangler
    n 1: an epiphytic vine or tree whose aerial roots extend down
         the trunk of a supporting tree and coalesce around it
         eventually strangling the tree [syn: strangler,
         strangler tree]
    2: someone who kills by strangling [syn: garroter,
       garrotter, strangler, throttler, choker]