n.
Pronunciation: ' äs-t ē - ə m
Function: noun
Inflected Form: plural os · tia \ -t ē - ə \
Etymology: New Latin, from Latin, door, mouth of a river; akin to Latin os mouth ― more at ORAL
Date: 1828
: a mouthlike opening in a bodily part (as a fallopian tube or a blood vessel)