The term biathlon weapon is a crossword solution that is five letters long and is spelled 'RIFLE'. A RIFLE is a type of firearm designed for accuracy and range, which makes it an ideal weapon for the biathlon. The biathlon is a winter sport that combines cross-country skiing and RIFLE shooting. Competitors ski around a track and then shoot at targets with their rifles. The winner is the competitor who completes the course in the shortest amount of time.