a score in American football; being in possession of the ball across the opponents' goal line
"The quarterback threw a perfect pass that helped his team secure the touchdown and take the lead."
a landing (as the wheels touch the landing field); especially of airplanes
"After circling for twenty minutes due to bad weather, the pilot finally managed to get a safe touchdown at the local airport."
A six-point score occurring when the ball enters possession of a team's player in the opponent's end zone.
"The quarterback threw a perfect pass that resulted in a touchdown just before halftime."