ˈästēˌōl noun
( -s )
Etymology: New Latin ostiolum, from Latin, small door, diminutive of ostium
: a small aperture, orifice, or pore: as
a. : the mouth of the perithecium or other spore fruit in a fungus or lichen
b. : an orifice of an odoriferous gland in various Hemiptera
c. : the opening of the conceptacle in various fucoid seaweeds
d. : one of the small inhalant orifices of a sponge