Definitions

1. noun

A parasitic or commensal flatworm, especially of the classes Monogenea and Digenea, that lives in the respiratory, urinary, or gastrointestinal tract of a vertebrate host.

“The researchers studied the lifecycle of a specific type of metastome that infects fish.”

2. noun

A small opening or pore, especially one in a plant or an animal.

“The tiny metastome on the leaf allowed for gas exchange between the plant and the atmosphere.”