motorboat

Any vessel driven by an engine (either inboard or outboard), but especially a small one.

To ride in a motorboat.

To press or bury one's face between the breasts of a woman; to press or bury one's face between the breasts of a woman and shake one's head, hum, or vibrate one's lips in imitation of a motorboat engine's sound.

ACT on Campus President Peter McCaffrey allegedly motorboated Heather Roy at the ACT Party offices over the newly-passed piece of legislation.

Kellie Pickler pretended to motorboat an imaginary pair of breasts to introduce Little Big Town's performance of “Pontoon,” […]

To press one's face into or between (something else).

'And we can fucking smash his dick in. Elliot's coming. And Hattie.' 'Are you lying?' 'I am not lying.' 'If you are lying, I am going to smash your dick in.' ... Amundsen pushes his whole head into the bowl, motorboating his food.

Immediately I started to lick, to suck, to kiss, to blow and to motorboat her pussy.

To press or envelope someone else's face into or between one's own breasts; to wrap one's breasts around someone's face or head.

She wanted to straddle him and motorboat him right there. She thought about his chest again, and his lips. His dark eyelashes made his dark chocolate eyes so much darker, especially when they softened with desire.

A man who was having trouble recalling an important piece of information put his head between his girlfriend's breasts and had her motorboat him. You might say the man was racking his brain trying to remember.