Blowhole (noun)

1. A hole or opening through which air or water is expelled, especially in cetaceans.
2. An opening in the roof of a cave or mine that allows air to circulate.

Origin:

The word 'blowhole' originated in the late 17th century and is derived from the old english 'blāwan' meaning 'to blow' and 'hol' meaning 'hole.'.

Examples:

1. The whale's blowhole was a spectacular sight as it expelled a burst of water into the air.
2. The dolphins often leap out of the water, giving the tourists a glimpse of their blowholes.
3. The blowhole in the cave was the source of fresh air that allowed the spelunkers to navigate the underground passageway.
4. The blowhole in the mine helped to dispel the dangerous gases, making it safer for the miners to work.
5. The blowhole in the volcano was a unique geological feature, with steam and smoke continuously being expelled from the opening.