Merriam-Webster Collegiate Dictionary - tentacle

 noun  Etymology: New Latin tentaculum, from Latin tentare to feel, touch — more at tempt  Date: circa 1762  1. any of various elongate flexible usually tactile or prehensile processes borne by animals and especially invertebrates chiefly on the head or about the mouth  2.  a. something that resembles a ~ especially in or as if in grasping or feeling out corruption spreading its ~s  b. a sensitive hair or emergence on a plant (as the sundew)  • ~d adjective