The REAL definition for blowholes is those things on whales' and dolphins' heads

A slang term for the mouth. Usually said when another is being annoying

This is a mustache ride in which the girl turns around so that your nose can slide into her vaginal hole. Then you breath out of your nose and send air into said hole.

A feature of coastal processes formed by erosion of a cliff or headland.

Waves quickly exploit joints, cracks and bedding planes in rock through hydraulic action. (Pressure is created when waves force air into crevices, pressure is released as waves retreat creating mini explosions.) Along the joint the sea will cut inland to form a cave. If the erosion continues upwards then with a little help from sub-aerial processes the line of erosion continues through the cliff to the top forming a blowhole. Blowholes get their name due to sea spray coming up and out in stormy weather much like a dolphin or whales blowhole.

asshole or anus; your sphincter

Part Two of the Whalecock Blowhole. At this point in the move, the male has just jizzed in his own asshole as a result of "Whalecocking." The masturbator will then proceed to fart at full power. The release of gas will cause the penis and fresh semen to fly out of the butthole in a sporadic and unpredictable manner often resulting in a poopy/cummy mess.

when a fat girl is wearing a tight shirt and you can see an indentation from the belly button. It looks like she has a blow hole.