Synonyms for alternate

verb

• be an understudy or alternate for a role
• reverse (a direction, attitude, or course of action)
• do something in turns
• go back and forth; swing back and forth between two states or conditions
• exchange people temporarily to fulfill certain jobs and functions

adjective

• serving or used in place of another
• occurring by turns; first one and then the other
• every second one of a series
• of leaves and branches etc; first on one side and then on the other in two ranks along an axis; not paired

noun

• someone who takes the place of another person