Question

Define the term wavelength.

Answer 1

The linear distance between the two consecutive particles of a vibrating medium in the same phase is called its wavelength. It is denoted by Greek letter lambda (λ).
OR
The distance travelled by the wave in one time period of vibration of the particles of medium is called its wavelength.
OR
In a longitudinal wave, distance between the two consecutive compressions or rare fractions is called wavelength.