Entry 1 sense Webster, 1913 Foully · Foul·ly · IPA /ˈfaʊl(l)i/ 01 v. In a foul manner; filthily; nastily; shamefully; unfairly; dishonorably. 1. In a foul manner; filthily; nastily; shamefully; unfairly; dishonorably. “I foully wronged him; do forgive me, do.” — Gay.