음속보다 빠른 속도로 비행하여 승객이나 화물을 운송하도록 설계된 초음속 수송기.
A civilian supersonic transport aircraft designed to fly faster than the speed of sound.
예문:
"The high operational costs eventually led to the retirement of the commercial SST."
"New technology is being developed to make the next generation of SST quieter."