/ded" set"/ for 1; 2; /ded" set'/ for 3
1. firmly decided or determined; resolved: His family was dead set against the marriage.
2. a serious or determined attempt; firm effort: He made a dead set at winning the championship.
3. Hunting. the stiff posture assumed by a hunting dog in indicating the presence and location of game.
[ 1840-50, Amer. ]