noun-modifying (irregular)
Prenominal adjective meaning 'much' or 'a lot of', used before nouns. A casual, somewhat playful loanword from Spanish.
from Spanish mucho
ムーチョな問題があって大変だ。
There are a lot of problems, so it's tough.
彼はムーチョな金を持っているらしい。
He seems to have a lot of money.