The word "appeasive" is not a common word in English, and its spelling may leave some puzzled. However, the IPA phonetic transcription can help explain it: /əˈpiːsɪv/. The first syllable is pronounced as "uh," followed by a long "e" sound. The second syllable is pronounced as "piss" (similar to the word "missive"), followed by a short "i" sound and a "v" sound. The word seems to be derived from the verb "appease," meaning to calm or soothe, and could be used as an adjective to describe something that has an appeasing effect.
Quieting.
Etymological and pronouncing dictionary of the English language. By Stormonth, James, Phelp, P. H. Published 1874.