air duct
air hole
air passage
air shaft
air tube
airway
armhole
avenue
blowhole
breathing hole
bullet-hole
bunghole
channel
chute
cringle
deadeye
debouch
door
egress
emunctory
escape
estuary
exhaust
exit
eye
eyelet
floodgate
flume
gasket
grommet
guide
keyhole
knothole
loop
loophole
louver
louverwork
manhole
mousehole
naris
nostril
opening
out
outcome
outfall
outgate
outgo
outlet
peephole
pigeonhole
coleoptera
orifice
porta
stigma
antennæ
avicularia
avicularium
bung
cingulate
deltoid
endwise
flipper
fontanel
lyddite
mediastinum
pylorus
quickset
rectocele
tarsi
thoracotomy
tibiae
touchhole
uveitis
volcanos