The Collaborative International Dictionary of English v.0.48:

Bloody sweat \Blood"y sweat`\
   A sweat accompanied by a discharge of blood; a disease,
   called sweating sickness, formerly prevalent in England and
   other countries.
   [1913 Webster]

Easton's 1897 Bible Dictionary:

Bloody sweat
   the sign and token of our Lord's great agony (Luke 22:44).