/chal"in jeuhr/ , n.
1. a person or thing that challenges.
2. Boxing. a boxer who fights a champion for his championship title.
3. Radio. interrogator (def. 2).
4. ( cap., italics ) U.S. Aerospace. the second space shuttle to orbit and return to earth: exploded 1 1 / 2 min. after launch on Jan. 28, 1986, causing the death of all seven on board.
[ 1250-1300; ME; see CHALLENGE, -ER 1 ]