adjective
- relating to or resembling an umbo, especially the beak-like projection on a bivalve shell
Usage: biological; technical
Examples
- The umbonal region of the clam shell showed signs of erosion.
- Researchers examined the umbonal cavity for growth patterns.
- The umbonal area is often the oldest part of a mollusk shell.
- Distinctive umbonal ridges helped identify the species.
- The umbonal sculpture varied between different bivalve specimens.