Question

One word substitution of the habit of walking in sleep

Answer 1

one word  substitution of the habit of walking in sleep is somnambulist  . 
but yet please check before writing this as an answer anywhere . it is the one i knew but maybe there exists another word for that particular purpose .. 

Answer 2

Answer :

One word substitution tests our ability to express the meaning of a phrase or a clause in a single word. These tests are helpful in determining the vocabulary and communication skills of an individual.

One word substitution of 'the habit of walking in sleep' is 'sleepwalking' or 'somnambulism' or 'noctambulism.'

Collins English Dictionary defines 'sleepwalking' as 'the act or practice of walking while asleep; somnambulism.'

Collins English Dictionary defines 'somnambulism' as 'a condition that is characterized by walking while asleep or in a hypnotic trance.'

Collins English Dictionary defines 'noctambulism' as 'walking in one's sleep; somnambulism.'