La Mojarra
no...the word is monumental yes It's a "portmanteau word" monumental + momentous = monumentous - means "very significant" first appearance in the year 1896 (google book search...)
It depends what sense you use those two words, monumental means something masive which could be use in a metaphorical sense to relate to major I suppose.
Monumental - album - was created in 2010.
Monumental Possession was created in 1996.
Monumental Church was created in 1814.
Torre Monumental was created in 1916.
Monumental Funk was created in 1974.
Monumental Life Insurance Company
Monumentality is the abstract noun form for the adjective monumental.
Americas involvement in the Iraq war is a monumental mistake.
Monumental Clock of Pachuca was created in 1910.