Pronunciation: [ˈɑːsənəm] (IPA) 
The word "arsenum" is not a correctly spelled word in English. However, it may resemble the word "arsenic," which has the IPA phonetic transcription of /ˈɑːsənɪk/. The letter "e" in "arsenum" does not correspond to any vowel sound in the word "arsenic," and the letter "m" also does not fit in the correct spelling. Thus, it is important to use proper spelling and pronunciation guidelines in order to effectively communicate in English.
The element arsenic, a steel-gray metal, symbol As, atomic weight 75, which forms a number of poisonous compounds, some of which are used in medicine.
A practical medical dictionary. By Stedman, Thomas Lathrop. Published 1920.
The word "arsenum" seems to be a misspelling or a variation of the word "arsenic". The etymology of "arsenic" can be traced back to the Greek word "arsenikon", meaning "yellow orpiment". It is believed that "arsenikon" was derived from the Persian word "زرنيخ" (zarnikh), referring to the same substance. The Latinized version of "arsenic" became "arsenicum", which eventually led to the current English term. The origins of the Persian word are uncertain.
