interchangeable

adj

1. (not-comparable)Freely substitutable; that may be swapped at will.

   “Eli Whitney's development of interchangeable parts was a breakthrough for modern manufacturing. Prior to that, each part had to be made custom.”

   “Constructional features of the railbus include the use of rubber suspension for axlebox/underframe and underframe/body mountings, the use of B.U.T. power transmission equipment, many components of which are interchangeable with those on British Railways standard railcars, power-operated sliding doors, and an absence of normal sidebuffers or drawgear.”

   “Sometimes the same words mean opposite things. Sometimes the opposite is true. Shock absorbers are called shocks. Slow down and slow up are interchangeable.”

   “The English, until relatively recently, seem to have imagined “English” and “British” to be interchangeable, as if Britain was just a bigger England.”

2. (not-comparable)Following each other in alternate succession; alternating.

noun

1. Anything that can be interchanged; a substitute.