Something that acts like a tentacle in its ability to grasp and hold.
2.
Any of various elongated tactile or prehensile flexible organs that occur on the head or near the mouth in many animals; used for feeling or grasping or locomotion.
... perpendicular cliffs that ran into the sea. Nina was out in a little boat alone, and the waves dashed the tiny craft nearer and nearer to the cave where the cuttlefish were waiting; finally she came so close that one tentacle seized her. Terrified, she awoke. After hours of half-waking, half-sleeping, formless confusion, she dreamed again. In this dream she and Giovanni were on horseback. She was sitting in a most precarious position on the horse's shoulder, but was held securely by Giovanni's arm around her waist. ... — The Title Market • Emily Post