manxome
/ˈmaŋks(ə)m/poetic nonce-wd.
adjective
A nonsense word invented by Lewis Carroll to describe the Jabberwock (an imaginary monster in the poem ‘Jabberwocky’): (perhaps) fearsome, monstrous.
Origin
Late 19th century; earliest use found in ‘Lewis Carroll’ (1832–1898), author, mathematician, and photographer (real name Charles Lutwidge Dodgson). From mank- + -some.