"Kips down" is a phrasal verb meaning to go to sleep or take a nap. There are several synonyms that can be used in place of "kips down" including doze, snooze, slumber, nap, and rest. Each of these words conveys a similar meaning of taking a brief period of time to rest and relax. "Doze" and "snooze" suggest a light, peaceful sleep, while "slumber" implies a deeper, longer sleep. "Nap" refers specifically to a short sleep taken during the day. "Rest" can also be used as a synonym for "kips down," as it suggests taking a break from activity to rejuvenate and re-energize.