trooper / trouper 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. 👇
trooper: (noun) a mounted policeman. (noun) a state police officer.
trouper: (noun) a person who is reliable and uncomplaining and hard working.
trooper: t·r·UW·p·er
trouper: NA
(Examples are Wikipedia snippets under the CC ShareAlike 3.0 license. Definitions drawn from WordNet.)