Wiktionary
n. 1 (context skiing English) An Alpine skiing discipline in which the course is longer, steeper and faster than normal slalom, and the gates are spaced at a greater distance. 2 (context snowboarding English) An Alpine snowboarding discipline derived from the skiing discipline
Wikipedia
Giant slalom (GS) is an alpine skiing and alpine snowboarding discipline. It involves skiing between sets of poles (gates) spaced at a greater distance to each other than in slalom but less than in Super-G.
Giant slalom and slalom make up the technical events in alpine ski racing. This category separates them from the speed events of Super-G and downhill. The technical events are normally composed of two runs, held on different courses on the same ski run.
Usage examples of "giant slalom".
The boat did a seam-stretching giant slalom run around three more large slate-colored mounds.
The tires squealed, the car shot forward, and he whipped from lane to lane, as if trying to make a car do what an Olympic skier could accomplish in a giant slalom.