The Collaborative International Dictionary of English v.0.48:
Railroad \Rail"road`\ (r[=a]l"r[=o]d`), Railway \Rail"way`\
1. A road or way consisting of one or more parallel series of
iron or steel rails, patterned and adjusted to be tracks
for the wheels of vehicles, and suitably supported on a
bed or substructure.
Note: The modern railroad is a development and adaptation of
the older tramway.
2. The road, track, etc., with all the lands, buildings,
rolling stock, franchises, etc., pertaining to them and
constituting one property; as, a certain railroad has been
put into the hands of a receiver.
Note: Railway is the commoner word in England; railroad the
commoner word in the United States.
Note: In the following and similar phrases railroad and
railway are used interchangeably:
Atmospheric railway, Elevated railway, etc. See under
Atmospheric, Elevated, etc.
Cable railway. See Cable road, under Cable.
Ferry railway, a submerged track on which an elevated
platform runs, for carrying a train of cars across a water
Gravity railway, a railway, in a hilly country, on which
the cars run by gravity down gentle slopes for long
distances after having been hauled up steep inclines to an
elevated point by stationary engines.
Railway brake, a brake used in stopping railway cars or
Railway car, a large, heavy vehicle with flanged wheels
fitted for running on a railway. [U.S.]
Railway carriage, a railway passenger car. [Eng.]
Railway scale, a platform scale bearing a track which forms
part of the line of a railway, for weighing loaded cars.
Railway slide. See Transfer table, under Transfer.
Railway spine (Med.), an abnormal condition due to severe
concussion of the spinal cord, such as occurs in railroad
accidents. It is characterized by ataxia and other
disturbances of muscular function, sensory disorders, pain
in the back, impairment of general health, and cerebral
disturbance, -- the symptoms often not developing till
some months after the injury.
Underground railroad Underground railway.
(a) A railroad or railway running through a tunnel, as
beneath the streets of a city.
(b) Formerly, a system of cooperation among certain active
antislavery people in the United States prior to 1866,
by which fugitive slaves were secretly helped to reach
Note: [In the latter sense railroad, and not railway, was
usually used.] "Their house was a principal entrep[^o]t
of the underground railroad." --W. D. Howells.