rail

A horizontal bar extending between supports and used for support or as a barrier; a railing.

Old Applegate, in the stern, just set and looked at me, and Lord James, amidship, waved both arms and kept hollering for help. I took a couple of everlasting big strokes and managed to grab hold of the skiff's rail, close to the stern.

The metal bar forming part of the track for a railroad.

A "moving platform" scheme[…]is more technologically ambitious than maglev trains even though it relies on conventional rails. Local trains would use side-by-side rails to roll alongside intercity trains and allow passengers to switch trains by stepping through docking bays.

A railroad; a railway, as a means of transportation.

We travelled to the seaside by rail.

a small Scottish village not accessible by rail

A conductor maintained at a fixed electrical potential relative to ground, to which other circuit components are connected.

ISA devices draw power from the +5 V, −5 V, +12 V, and −12 V rails of the power supply unit.

There has been another, fairly gradual change in the ATX specification: Initially a lot of power was supplied on the 5V and 3.3V rails, but over time more and more power shifted to 12V because it's more efficient. Modern (ATX12V 2.x) PSUs supply most of their power on the 12V rail and not a lot on the 5V rail, which means a modern PSU may not be able to supply an old board, unless it's a really beefy PSU—because providing 500W on the 12V rail is of very little use to an AT or early ATX system.

A horizontal piece of wood that serves to separate sections of a door or window.

To travel by railway.

Mottram of the Indian Survey had ridden thirty and railed one hundred miles from his lonely post in the desert […]

To place on a track.

To enclose with rails or a railing.

It ought to be fenced in and railed.

To range in a line.

They were brought to London all railed in ropes, like a team of horses in a cart.

To sexually penetrate in a rough manner.

Any of several birds in the family Rallidae.