wastefulness n. + Add to list US //ˈweɪstfəɫnəs// UK //wˈeɪstfəlnəs// waste·ful·ness SynonymsEtymology Synonyms dissipationthriftlessnesswasteOriginMEwastfulnes→ENwastefulness From Middle English wastfulnes; equivalent to wasteful + -ness.