alternate

(s) every second one of a series
- the cleaning lady comes on alternate Wednesdays
- "jam every other day"- the White Queen
(s) serving or used in place of another
- an alternative plan
alternative, substitute,
(s) occurring by turns; first one and then the other
- alternating feelings of love and hate
alternating,
(a) of leaves and branches etc; first on one side and then on the other in two ranks along an axis; not paired
- stems with alternate leaves

(v) go back and forth; swing back and forth between two states or conditions jump,
(v) exchange people temporarily to fulfill certain jobs and functions
(v) be an understudy or alternate for a role understudy,
(v) reverse (a direction, attitude, or course of action) flip-flop, interchange, tack, switch, flip,
(v) do something in turns
- We take turns on the night shift
take turns,

jump surrogate replacement alternative substitute understudy alternating flip-flop interchange tack switch flip take turns

opposite paired

alternately