domatium
/dɒˈmeɪʃəm/Definitions
1. noun
A small chamber or cavity in a plant’s leaf, especially one containing a midrib or a vein.
“The botanist studied the tiny domatium within the leaf of the tropical plant.”
2. noun
In some insects, a cavity or chamber within a plant that serves as a shelter or protection.
“The ants made their home in the domatium of the leaf, safe from predators.”