predatory adj.

mid-13c., preie, "animal hunted for food, that which is seized by any carnivorous animal to be devoured" (also, figuratively, of souls captured by Satan, etc.), also "goods taken in war," from Old French preie "booty, animal taken in the chase" (mid-12c., Modern French proie), from Latin praeda "booty, plunder; game hunted."

This is from earlier praeheda, literally "something seized before," from PIE *prai-heda-; for the first element see prae-; the second element is related to the second element in prehendere "to grasp, seize" (from PIE root *ghend- "to seize, to take").

The meaning "act of preying or seizing upon anything" is from early 14c.; bird of prey is from late 14c. (fowl of prey is mid-14c.).

also *ghed-, Proto-Indo-European root meaning "to seize, to take." 

It forms all or part of: apprehend; apprentice; apprise; beget; comprehend; comprehension; comprehensive; comprise; depredate; depredation; emprise; enterprise; entrepreneur; forget; get; guess; impresario; misprision; osprey; predatory; pregnable; prehensile; prehension; prey; prison; prize (n.2) "something taken by force;" pry (v.2) "raise by force;" reprehend; reprieve; reprisal; reprise; spree; surprise.

It is the hypothetical source of/evidence for its existence is provided by: Greek khandanein "to hold, contain;" Lithuanian godėtis "be eager;" second element in Latin prehendere "to grasp, seize;" Welsh gannu "to hold, contain;" Russian za-gadka "riddle;" Old Norse geta "to obtain, reach; to be able to; to beget; to learn; to be pleased with;" Albanian gjen "to find."