A peduncle is an elongated stalk of tissue.
Sessility is the state of not having a peduncle; a sessile mass or structure lacks a stalk.
[1] In medicine, a mass such as a cyst or polyp is said to be pedunculated if it is supported by a peduncle.
[3] Pedunculated eyes are also the defining attribute of the stylophthalmine trait found in certain fish larvae.
The caudal peduncle is a slightly narrowed part of a fish where the caudal fin meets the spine.