cirrous / cirrus / serous 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. 👇
cirrous: NA
cirrus: (noun) usually coiled. (noun) a wispy white cloud (usually of fine ice crystals) at a high altitude (4 to 8 miles). (noun) a slender flexible animal appendage as on barnacles or crinoids or many insects; often tactile.
serous: (adjective) of or producing or containing serum.
cirrous: NA
cirrus: s·IH·r·ah·s
serous: NA
(Examples are Wikipedia snippets under the CC ShareAlike 3.0 license. Definitions drawn from WordNet.)