The story
From kayak + slalom. From using kayak boats on a slalom course.
Etymology from Wiktionary, CC BY-SA 4.0.
Today it means: A watersports discipline, competitors race singly against the clock, on a whitewater course with downstream and upstream gates, which competitors must pass on the correct side in the correct direction, competing in kayaks. Full definition →
From kayak + slalom. From using kayak boats on a slalom course.
Etymology from Wiktionary, CC BY-SA 4.0.