A rectangular hole or slot.
A hidden container that holds a logbook and rubber stamp, found by following clues as a form of recreation.
A delivery point for mail, a box, compartment or slot for this purpose.
A collection point for mail intended for onward delivery, a secure box or receptacle for this purpose.
To transfer a widescreen motion picture to home video formats while preserving the original aspect ratio, with the placing of black bars above and below the picture area.
To hunt for letterboxes (containers with logbook and rubber stamp) by following clues.
Transferred to home video formats while preserving the original aspect ratio, having black bars above and below the picture area.
Anything that is hollow and cylindrical in shape.
The London Underground railway system, originally referred to the lower level lines that ran in tubular tunnels as opposed to the higher ones which ran in rectangular section tunnels. (Often the tube.)
A television. Compare cathode ray tube and picture tube.
A tin can containing beer.
An approximately cylindrical container, usually with a crimped end and a screw top, used to contain and dispense semiliquid substances.
An idiot.
A wave which pitches forward when breaking, creating a hollow space inside.
To supply with, or enclose in, a tube.
To intubate.
To ride an inner tube.