Word parts firm + -ness Pronunciation (US) IPA (key): /ˈfɝmnəs/ (UK) IPA (key): /ˈfɜːmnəs/ Audio (US)(file) Hyphenation: firm‧ness Noun Singular firmness Plural none The firmness of something is how firm the thing is.Wikiwand - on Seamless Wikipedia browsing. On steroids.Remove ads