say it: WAYST-fuhl
wasteful is an adjective meaning "inefficient in use of time and effort and materials". It carries 3 recorded senses.
inefficient in use of time and effort and materials
“a clumsy and wasteful process”
“wasteful duplication of effort”
“uneconomical ebb and flow of power”
tending to squander and waste
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 wasteful 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.