Mid 18th century; earliest use found in Alexander Pope (1688–1744), poet. Either from post-classical Latin superlunarissuperlunary, or independently from super- + lunar, after sublunar.
Definition of superlunar in US English:
superlunar
adjective
Superlunary.
Origin
Mid 18th century; earliest use found in Alexander Pope (1688–1744), poet. Either from post-classical Latin superlunaris superlunary, or independently from super- + lunar, after sublunar.