psychosis / sycosis are similar-sounding terms with different meanings (referred to as homophones). To better understand the differences, see below for definitions, pronunciation guides, and example sentences using each term. 👇
psychosis: (noun) any severe mental disorder in which contact with reality is lost or highly distorted.
sycosis: NA
psychosis: s·ay·k·OW·s·ah·s
sycosis: NA
(Examples are Wikipedia snippets under the CC ShareAlike 3.0 license. Definitions drawn from WordNet.)