spiracle (n.)

• airway
• armhole
• avenue
• blowhole
• bunghole
• channel
• chute
• cringle
• deadeye
• door
• egress
• escape
• estuary
• exhaust
• exit
• eye
• eyelet
• floodgate
• flume
• gasket
• grommet
• guide
• keyhole
• knothole
• loop
• loophole
• louver
• manhole
• naris
• nostril
• opening
• out
• outcome
• outfall
• outgo
• outlet
• peephole
• pigeonhole
• pinhole
• placket
• pore
• port
• porthole
• shaft
• sluice
• spout
• tap
• transom
• vent
• venthole
• ventilator
• vomitory
• weir