High-speed means built to run at very great velocity. A high-speed line.
It is used of trains, of chases and of internet connections alike. A high-speed railway costs several times an ordinary one, mostly because the curves must be enormous.
1adjectivehigh-speedOf a train, chase, or internet line: built to run at very great velocity.
“The high-speed service cut the journey in half.”
high-speed is a quality.