The word "hydrozone" is spelled with a "d" and not a "t" despite the "t" sound being heard when pronounced. This is because "hydro-" is derived from the Greek word "hudro-" which begins with a voiced fricative consonant [ð] instead of a voiceless one [θ]. Therefore, the correct spelling is "hydrozone" [haɪdrəzoʊn]. Accurate phonetic transcription is important for clear communication and understanding in both written and spoken language.
Trade name of an aqueous solution of hydrogen peroxide.
A practical medical dictionary. By Stedman, Thomas Lathrop. Published 1920.