Question

with reference to sound what do you mean by frequency and wavelength

Answer 1

Frequency is the number of occurrences of a repeating event per unit time
 the wavelength of a sinusoidal wave is the spatial period of the wave

Answer 2

With reference to sound waves,


Frequency means the number of oscillations completed by the sound wave in 1 second. It is denoted by f. It is also the reciprocal of Time Period.
So, f = 1/T

Wavelength means the distance between any two condensations or the distance between any two rarefactions. (Since sound is a longitudinal wave). It is denoted by Greek letter λ (Lambda).