Monumental means enormous, or worthy of a monument. A monumental achievement, a monumental mistake, monumental scale.
It works in both directions and just as happily for disasters as for triumphs: a monumental blunder is as fixed a phrase as a monumental achievement. Applied to architecture and sculpture it means built on the scale of monuments. Note monumental masonry, which is the trade of making gravestones and is the most literal use of the word left.
1adjectivemonumentalEnormous in scale or importance.
“Building the railway across the mountains was a monumental task.”
2adjectivebuiltBuilt on the scale of monuments.
“The capital is full of monumental government buildings with huge stone columns.”
monumental is a quality of great scale.
Latin monumentalis comes from monumentum, a memorial, from monere, to remind or warn. Monitor, admonish and money come from the same warning.
Latin
monumentālis
English, today
monumental
Borrowed from Latin monumentālis, from Latin monumentum; equivalent to monument + al.
Etymology from Wiktionary, CC BY-SA