the convergence of two parallel railroad tracks in a narrow place; the inner rails cross and run parallel and then diverge so a train remains on its own tracks at all times
the capacity to understand a broad range of topics; "a teacher must have a breadth of knowledge of the subject"; "a man distinguished by the largeness and scope of his views"
a device for showing the operating condition of some system
a signal for attracting attention
(chemistry) a substance that changes color to indicate the presence of some ion or substance; can be used to indicate the completion of a chemical reaction or (in medicine) to test for a particular reaction