me·a·tus 
(mē-ātəs)
(mē-ātəs)n. pl. me·a·tus·es or meatus
A body opening or passage, such as the opening of the ear or the urethral canal.
[Latin meātus, passage, from past participle of meāre, to pass; see mei-1 in the Appendix of Indo-European roots.]
me·atal (-təl) adj.