Definitions

1. verb

to form or have a hump or prominence, especially on the back or top

“The fossilised shell was umbonate, featuring a distinctive hump at the top.”

2. adjective

having or characterized by a hump or prominence, especially on the back or top

“The scientist examined the umbonate structure of the ancient shell, trying to understand its purpose.”

3. noun

a hump or prominence, especially on the back or top of something

“The umbonate of the shell caught the eye of the naturalist, who was studying the species.”