| n. | 1. | (Zool.) The central axis or cord in the tail of larval ascidians and of certain adult tunicates. |
| Noun | 1. | urochord - primitive marine animal having a saclike unsegmented body and a urochord (a notochord) conspicuous in the larva Synonyms: tunicate, urochordate |
| 2. | urochord - a notochord of a larval tunicate typically confined to the caudal region |