ETYM Latin alternatus, p. p. of alternate, from alternus. Related to Altern, Alter.
1. Allowing a choice; SYN. alternative.<br />
2. Occurring by turns; first one and then the other; SYN. alternating.
3. Every second one of a series; SYN. every other.
4. (Botany) Of leaves and branches etc; first on one side and then on the other in two ranks along an axis; not paired.