Sanakirja.org

Määritelmät

Adjektiivi

1. (of a sound, scientific) having a frequency too low to be audible
2. (of a sound, literary) very quiet, almost inaudible
3. (of a speed) (aviation) less than the speed of sound (in the same medium, and at the same temperature and pressure)
4. (fluid mechanics, of a flow) with a Mach number such that 0.3 < Ma < 0.8 (approximately - the exact limits vary between sources)

Substantiivi

1. an aircraft whose maximum speed is less than the speed of sound