The definition of a trooper is a soldier, police officer or cavalry horse, or is slang for a person who is willing to participate in difficult situations.
An example of a trooper is a cop who patrols the highways.
An example of a trooper is a person who agrees to take on additional responsibility even though they have very little free time.
"trooper." YourDictionary, n.d. Web. 13 April 2019. <https://www.yourdictionary.com/TROOPER>.
a. A member of a unit of cavalry.
a. A mounted police officer.
b. A state police officer.
also trouper A reliable, uncomplaining, often hard-working person.
(military) A soldier of private rank in cavalry or armour. Abbreviated Tpr.
One who endures adversity or hardship with an attitude of stoicism and persistence.
He was a real trooper about taking care of the kids for the weekend.
From troop +"Ž -er, from French troupe.
Sense of cavalry soldier attested 1640, mounted policeman 1858 (Australia), state policeman 1911 (US). The sense of "one who endures adversity" comes from English trouper (“member of an acting troupe"), 1959, but through assimilation with the sense of "soldier" has come to be usually spelled "trooper".
Less than fifteen minutes later, a state trooper car pulled into the yard.
The trooper gave Alex a strange look and then glanced at Lori, who seemed a loss for words.
Her killer was pulled over the next day by an observant trooper shortly after dumping the young girl's body.
But three earls of his own house - Carlisle, Suffolk and Berkshire - and the Lord Howard of Escrick, an ex-trooper of Cromwell's guard and an anabaptist sectary, gave their votes against him, his nephew Mowbray being the only peer of his name in the minority for acquittal.