Late 16th century; earliest use found in Thomas Newton (d. 1607), translator and Church of England clergyman. From post-classical Latin alternalis from classical Latin alternus + -ālis.
Definition of alternal in US English:
alternal
adjective
rare
Alternate.
Origin
Late 16th century; earliest use found in Thomas Newton (d. 1607), translator and Church of England clergyman. From post-classical Latin alternalis from classical Latin alternus + -ālis.