Synonyms for Wasteful (same or very similar meaning)
WordNet sense 1 (wasteful of resources):
uneconomic, uneconomicalWordNet sense 2 (recklessly wasteful):
extravagant, prodigal, profligateWordNet sense 3 (not producing desired results; wasteful):
inefficientWordNet sense 4 (causing destruction or much damage):
destructiveFrom the ODE community, based on WordNetadd/edit