heads up

/ˈhɛdzˌʌp/
noun
  1. A warning or piece of advance information about something that is going to happen.
    • The manager gave us a heads-up that the meeting would start early.
    • I got a heads-up from my friend that the store is having a sale tomorrow.
    • Thanks for the heads-up about the traffic jam; I took a different route.
Antonyms
adjective
  1. Alert and paying attention; watchful.
    • Stay heads-up during the test so you don't miss any instructions.
    • The hikers remained heads-up for any signs of wildlife on the trail.
    • A good driver is always heads-up and aware of other cars.
Antonyms
What does "heads up" mean? | whatsthatwordmean | whatsthatwordmean