subumbrella
/ˌsʌbʌmˈbrɛlə/
noun
- The concave underside of the bell-shaped body of a jellyfish or other cnidarian.
- Scientists study the subumbrella to understand how jellyfish move through water.
- The jellyfish's tentacles hang down from the subumbrella.
- The subumbrella contains the mouth and digestive structures of the jellyfish.