What does "proboscis" mean?

Proboscis: (Zoöl.) By extension, applied to various tubelike mouth organs of the lower animals that can be everted or protruded. Note: The proboscis of annelids and of mollusks is usually a portion of the pharynx that can be everted or protruded. That of nemerteans is a special long internal organ, not connected with the mouth, and not used in feeding, but capable of being protruded from a pore in the head. See Illust. in Appendix.