Meatus

In anatomy, a meatus /miːˈeɪtəs/, plural "meatus" or "meatuses", is a natural body opening or canal.

Examples include:

(The plural forms of "meatus" are: meatus, as a Latin form (of the fourth declension noun class, which the word belongs to); or meatuses, as a normally derived English plural; or often, and incorrectly, meati, by false analogy with the very common Latin -us/-i forms (such as alumnus/alumni), i.e., the second declension noun class.)

...
Wikipedia