protrusible
/prəʊˈtruːsəbl/adjective
- Zoology (of a body part, such as the jaws of a fish) capable of being protruded or extended【动】（鱼下巴等）可伸出的, 可突出的。
词源
mid 19th cent.: from Latin protrus- 'extended or thrust forward' （from the verb protrudere）+-IBLE.