From The Collaborative International Dictionary of English v.0.48:
taxicab \tax"i*cab\, n.
an automobile with a professional driver which can be hired
to carry passengers; -- also called a taxi, and informally
called a cab or a hack. The driver of a taxicab is
referred to as a cab driver or cabbie, and sometimes as a
chauffeur or hackie.
Note: Taxicabs may be engaged by a prior appointment made,
e.g. by telephone, or they may cruise for passengers,
i.e. they may drive in city streets and stop to pick up
pasengers when they are signalled by a prospective
passenger. The act of signalling a taxicab (usually by
a wave of the arm) is often called
to flag down a cab.
[PJC]
From The Collaborative International Dictionary of English v.0.48:
Cab \Cab\ (k[a^]b), n. [Abbrev. fr. cabriolet.]
1. A kind of close carriage with two or four wheels, usually
a public vehicle. "A cab came clattering up." --Thackeray.
[1913 Webster]
Note: A cab may have two seats at right angles to the
driver's seat, and a door behind; or one seat parallel
to the driver's, with the entrance from the side or
front.
[1913 Webster]
Hansom cab. See Hansom.
[1913 Webster]
2. The covered part of a locomotive, in which the engineer
has his station. --Knight.
[1913 Webster]
From The Collaborative International Dictionary of English v.0.48:
Cab \Cab\ (k[a^]b), n. [Heb. qab, fr. q[=a]bab to hollow.]
A Hebrew dry measure, containing a little over two (2.37)
pints. --W. H. Ward. --2 Kings vi. 25.
[1913 Webster]