<span class="searchmatch">harmfuller</span> (rare) comparative form of harmful: more harmful...
/ˈhɑːmfl̩/ (General American) IPA(key): /ˈhɑɹmfl̩/ harmful (comparative <span class="searchmatch">harmfuller</span> or more harmful, superlative harmfullest or most harmful) Causing or likely...