subsonic
🇺🇸
/ˌsʌbˈsɑːnɪk/
🇬🇧
/ˌsʌbˈsɒnɪk/
adjective
R
Moving slower than the speed at which sound travels.
The subsonic aircraft was designed for quiet and efficient travel.
亞音速飛機被設計用於安靜高效的旅行。
translation
亞音速的