Explanation:

Slower process

In simple words, retreating means withdrawal. So, withdrawal of south-west monsoon winds from skies of north India during months of October and November is known as retreating monsoon. The withdrawal is gradually and takes about three months.
Retreating monsoon: With retreat of the monsoons, the clouds disappear and the sky becomes clear. The day temperature starts falling steeply. Monsoon rains weakens all over India except few south eastern states. Monsoon trough weakens and gradually shifts south wards Most severe and devastating tropical cyclones originate in the Indian seas especially in the Bay of Bengal due to retreating monsoons. Direction of winds is from North west to south east and Winds blow from surface to sea there by carrying no moisture.