Substitution of one thing for another; interchange.
The reversal of an electric current.
The change to a lesser penalty or punishment by the State
Substitution, as a means of discriminating between phonemes.
The process or habit of journeying to and from work on a regular basis; commuting.
Specifically, the substitution of one kind of payment for another, especially a switch to monetary payment from obligations of labour.
The condition of being interdependent.