ascidian

American  

[uh-sid-ee-uhn] / əˈsɪd i ən /

noun

1. any solitary or colonial tunicate of the class Ascidiacea, exhibiting in the larval stage the vertebrate characteristics of a notocord and hollow nerve cord.

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adjective

1. belonging or pertaining to the class Ascidiacea.

ascidian British  

/ əˈsɪdɪən /

noun

1. any minute marine invertebrate animal of the class Ascidiacea, such as the sea squirt, the adults of which are degenerate and sedentary: subphylum Tunicata (tunicates)

2. the free-swimming larva of an ascidian, having a tadpole-like tail containing the notochord and nerve cord

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adjective

1. of, relating to, or belonging to the Ascidiacea

Etymology

Origin of ascidian

1855–60; < New Latin Ascidi ( um ) a tunicate genus ( see ascidium) + -an