Examples from the Web for challenger
It was not until after the Challenger accident that the folly of this approach was realized.
It could have had a burn-through like Challenger Shuttle, but I would have thought that would take longer.Clues From SpaceShipTwo’s Wreckage: Did the Crew Compartment Fail?|Clive Irving|November 2, 2014|DAILY BEAST
Incumbent Democrat Kay Hagan is steadily but narrowly leading GOP challenger Thom Tillis.
The president wants to stay; the challenger wants to go back to his hotel.Behind the Scenes With a ‘Site Agent’: The Secret Service’s Hardest Job|Marc Ambinder|October 2, 2014|DAILY BEAST
He is technically running against incumbent Republican Mitch McConnell and Democratic challenger Alison Lundergan.
Dan's teeth snapped closed, then parted to grin at his challenger.The Best Short Stories of 1917|Various
When the duel is terminated, the challenger passes on to his adversary the hair which he had temporarily inherited.The Elementary Forms of the Religious Life|Emile Durkheim
The contest was obstinate, and terminated in the death of the challenger.Edgar Huntley|Charles Brockden Brown
But then it must not be forgotten that the challenger is a "Long" shot.Punch - Volume 25 (Jul-Dec 1853)|Various
Challenger and Summerlee have treated the matter in a joint scientific paper, but to me alone was left the popular account.The Poison Belt|Arthur Conan Doyle
Word Origin and History for challenger
late 13c., "a claimant;" mid-14c., "one who makes false charges;" mid-15c., "one who disputes something, objector," from Anglo-French chalengeour (Old French chalongeor "slanderer, petitioner, plaintiff"), agent noun from challenge (v.). Specific sense of "one who calls out another in a contest" is from 1510s.