say it: ROO-i-ning
ruining is a noun meaning "destruction achieved by causing something to be wrecked or ruined". It carries one recorded sense.
destruction achieved by causing something to be wrecked or ruined
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 ruining 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.