heads-up

1. advance notice

2. a warning

Just wanted to give you a heads up so you'll be expecting his call.

heads-up

a warning, especially of danger or the need to be alert

Heads-up. There's a situation out there.

heads-up

A term in many competitive games for 1 on 1 competition. One of its more common uses is in card games where the value of hands can change due to the number of people playing. Heads-up offers favoriable odds for high cards like aces and kings, even with sub-par kickers.

I went heads-up with Tyler and beat him with a boat on the river.

heads-up

A business buzzword meaning to give somebody a summary or progress report on the current situation.
Mainly used by idiots who want to be something they're not, ie successful businessmen.

Let me give you a heads-up on the current state of play.

heads-up

an advance notice given when a person stakes a claim to something or somewhere, often shouted as said person is running or when a group of people are given a variety of some sort.
similar to "dibs on" or "i call"

sibling (to sibling)"i got heads up on
the passenger side"

jerry (to group) "i got heads up on the green m&m's"

gord (to friends) "i got heads up on the Playstation"

heads up

Advance notice of something that will need attention.

Just a heads up that the customer is likely to escalate this problem...

a heads up

To give someone a warning of iminent danger, trouble or strife.

Dude - Jonny's banging Daves wife! I best call him and give him a heads up!