Late 19th century; earliest use found in John Addington Symonds (1840–1893), writer and advocate of sexual reform. From mytho- + poet, after mythopoetry.
Definition of mythopoet in US English:
mythopoet
nounˈmɪθə(ʊ)ˌpəʊɪt
A writer of mythic poetry; a mythopoeic writer.
Origin
Late 19th century; earliest use found in John Addington Symonds (1840–1893), writer and advocate of sexual reform. From mytho- + poet, after mythopoetry.