inner tube

noun

1. a doughnut-shaped, flexible rubber tube inflated inside a tire to bear the weight of a vehicle.

inner tube

noun

1. an inflatable rubber tube that fits inside a pneumatic tyre casing

Word History and Origins

Origin of inner tube¹

First recorded in 1890–95

Example Sentences

Each summer, thousands of people boat, kayak or float on inner tubes on the river, which boasts whitewater areas as well as trout and salmon fisheries.

From BBC

An 11-year-old girl has been rescued after clinging to inner tubes for three days in stormy weather in the Mediterranean.

From BBC

“Also, do not tie two or more inner tubes together; this requires you to have a life jacket for each person. Kids 12 and younger must wear a life jacket.”

From Los Angeles Times

Pomeroy’s family told Portland Monthly that the accident occurred when their inner tubes, which were tied together, flipped over in fast-moving currents after hitting a snag on the Willamette River.

From Salon

Consider the analogy of trying to capture a 3D image of a child wearing an inner tube around their waist.

From Science Daily