IPA: /ˈtʌʧdaʊn/
KK: /ˈtʌʧˌdaʊn/
The moment when an aircraft or spacecraft lands on the ground, or the act of scoring points in American football by crossing the opponent's goal line with the ball.
The football team celebrated after their player scored a touchdown.
Touchdown → It is formed from "touch" (from Old English *tūcan*, meaning to come into contact with) and "down" (meaning a downward direction or position). The word "touchdown" refers to the act of coming into contact with the ground, particularly in sports like football when a player scores by getting the ball into the end zone and touching the ground with it.
Think of the action of coming into contact ('touch') with the ground ('down') — that's what a touchdown means in sports.
No commonly confused words.