| verb | go back and forth; swing back and forth between two states or conditions |
| verb | exchange people temporarily to fulfill certain jobs and functions |
| verb | be an understudy or alternate for a role |
| verb | reverse (a direction, attitude, or course of action) |
| verb | do something in turns “We take turns on the night shift” |
| adjective | (of a current) reversing direction “alternating current” |
| adjective | occurring by turns; first one and then the other “alternating feelings of love and hate” |
| alternation | noun | successive change from one thing or state to another and back again |
| alternate | noun | someone who takes the place of another person |
| understudy | noun | an actor able to replace a regular performer when required |
| tack | noun | (nautical) the act of changing tack |
| switch | noun | an event in which one thing is substituted for another |
| flip-flop | noun | a decision to reverse an earlier decision |