Truttaceous is a rare word from the field of zoology, used to describe a group of fish with similar physical characteristics. The correct spelling is pronounced as /trəteɪʃəs/, where the first syllable is pronounced like "truh" and the second syllable is pronounced like "tay". The "ceous" ending indicates that this word is an adjective, meaning "resembling or related to trout". While not commonly used in everyday conversation, truttaceous is an important word for those studying fish and aquatic life.