Definitions

1. noun

A small opening, especially one in a shellfish, such as a bivalve or a snail, that serves as the respiratory aperture.

“The oscule of the coral reef allowed water to flow in and out, facilitating respiration.”

2. noun

In some types of sponges, an opening through which water is drawn into the sponge.

“The oscules of the sponge allowed it to filter water efficiently and extract nutrients.”