light sleep vs short sleep

light sleep and short sleep both are nouns.

Word	Noun	Adjective	Verb	Adverb
light sleep	Yes	No	No	No
short sleep	Yes	No	No	No

As nouns, light sleep and short sleep are synonyms defined as:

light sleep and short sleep: sleeping for a short period of time (usually not in bed)

Other synonyms of light sleep include catnap, forty winks, nap, snooze.

light sleep (noun)	short sleep (noun)
sleeping for a short period of time (usually not in bed)	sleeping for a short period of time (usually not in bed)