say it: MAHN-struhs
monstrous is an adjective meaning "abnormally large". It carries 3 recorded senses.
abnormally large
shockingly brutal or cruel
“murder is an atrocious crime”
“a grievous offense against morality”
“a grievous crime”
“no excess was too monstrous for them to commit”
Forms marked · are formed by the regular rule rather than recorded in the source data. English keeps a few hundred irregulars and the rest follow the pattern, so the rule is right far more often than not — but it is a rule, and the mark says so.
Definitions, synonyms and semantic relations for monstrous come from Princeton University’s WordNet. The pronunciation comes from the CMU Pronouncing Dictionary. Commonness is measured against a corpus of everyday English. Full sources and licences.