"Thornhead" is spelled with the IPA phonetic transcription /ˈθɔrnˌhɛd/. The first syllable, "thorn," is pronounced with the voiceless dental fricative /θ/ followed by the rounded vowel /ɔ/. The second syllable, "head," is pronounced with the unrounded vowel /ɛ/ and the voiced velar fricative /ɣ/. The spelling of "thornhead" accurately represents its pronunciation using the English alphabet. The word "thornhead" refers to a fish with a sharp protrusion on its head, resembling a thorn.