It's not in Merriam-Webster, but here's my best shot:
PREDATORINESS
There is a larger word following on from DESPERATIONS:
E N D O P A R A S I T E S
ENDOPARASITES is the word size-limit, and new record with 13 Letters.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
D O E
and finally...
D E S P O L I A T I O N S
~~~~~~~~~~~~~~~~~~~~~
G U N