sleep on

sleep on (someone or something)

slang To fail to appreciate or ignore the significance of someone or something. Typically used as an imperative. Don't sleep on this song—it's so good! A lot of people slept on this team coming into the playoffs, but now everyone is waking up to how good they are.
See also: on, sleep

sleep on (something)

To postpone a decision until the following day so that one has additional time to consider it. Why don't you sleep on the offer and let us know your decision in the morning? I'm still not sure if I'm ready to spend that much money. Can I sleep on it?
See also: on, sleep
Farlex Dictionary of Idioms.

sleep on something

 
1. Lit. to recline on something and slumber. I like to sleep on a firm bed. Mary had to sleep on the floor because her sister was visiting.
2. Fig. to postpone a decision until one has slept through the night. (As if one were going to think through the decision while sleeping.) It sounds like a good idea, but I'd like to sleep on it before giving you my response. You go home and sleep on it and give me your answer in the morning.
See also: on, sleep
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs.

ˈsleep on it

not make a decision until the following day so that you can have more time to think about it: If you aren’t sure what to do, sleep on it and give us your decision tomorrow.
See also: on, sleep
Farlex Partner Idioms Dictionary

sleep on

v.
To think about something overnight before deciding: If you can't make a decision right now, sleep on it, and give me your answer in the morning.
See also: on, sleep
The American Heritage® Dictionary of Phrasal Verbs.
See also:
  • count in
  • be sure to (do something)
  • be sure to do something
  • buzz off
  • come in
  • come in a certain position
  • come on in
  • cheer up
  • Cut it out!
  • cut out