Synonyms for Damaging (same or very similar meaning)
WordNet sense 1 ((sometimes followed by `to') causing harm or injury):
detrimental, prejudicial, prejudicious
WordNet sense 2 (causing or capable of causing harm):
harmful
WordNet sense 3 (designed or tending to discredit, especially without positive or helpful suggestions):
negative
From the ODE community, based on WordNet
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