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Definitions

heads up

ADJECTIVE
alert
Synonyms
STRONGEST
active bright careful intelligent observant perceptive sharp vigilant wary watchful wired wise
STRONG
hip jazzed quick ready spirited
WEAK
all ears cagey circumspect clever fast on the draw good hands heedful on guard on one's toes on the ball on the job on the lookout on the qui vive psyched-up switched on wide-awake with it
Antonyms
STRONGEST
careless dull foolish ignorant inattentive incautious indifferent indiscreet lazy negligent stupid thoughtless unaware unintelligent unobservant
STRONG
slow uneducated
WEAK
asleep drowsy lethargic sluggish weary
ADJECTIVE
on the ball
Synonyms
WEAK
active all ears attentive bright cagey careful clever good hands intelligent lively observant on guard on one's toes on the job on the lookout on the stick perceptive quick ready sharp spirited vigilant watchful wise with it
ADJECTIVE
open-eyed
Synonyms
WEAK
active all ears bright cagey careful circumspect clever fast on the draw good hands heedful hip intelligent jazzed observant on guard on one's toes on the ball on the job on the lookout on the qui vive perceptive psyched-up quick ready sharp spirited switched on vigilant wakeful wary watchful wide-awake wired wise with it
ADJECTIVE
wide-awake
Synonyms
WEAK
active alert all ears attentive bright bright-eyed and bushy-tailed fast on the draw intelligent lively on guard on one's toes on the ball on the job on the lookout psyched-up quick ready sharp spirited vigilant watchful wide-eyed wired
NOUN
warning
Synonyms
STRONGEST
admonition advice alarm alert caution example guidance hint indication information lesson notification prediction recommendation sign signal suggestion threat word
STRONG
Mayday SOS augury caveat exhortation fore foretoken forewarning injunction intimation omen portent premonition presage tip tip-off token wink
WEAK
distress signal handwriting on the wall look out watch-it word to the wise
Antonyms
STRONGEST
misinformation
VERB
look out
Synonyms
WEAK
be alert be careful be on guard beware check out have a care hearken keep an eye out keep tabs listen mind notice pay attention peg pick up on scope shotgun size up spot spy watch out
Antonyms
WEAK
disregard ignore neglect

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

A favorite tactic was to slip into a flock of sleeping birds in a “sneak” boat and slap its sides just before the shot to get the birds’ heads up.

From The Wall Street Journal • Mar. 23, 2026

It feels a little bit like Skynet giving us a heads up before incinerating the atmosphere, but I’ll take it.

From Slate • Feb. 8, 2026

Tarang Amin, who heads up e.l.f.—known for its affordable cosmetics and skin care—said the company’s value proposition was resonating with consumers across income and age demographics.

From Barron's • Feb. 6, 2026

Walz later said that he issued Minnesota’s National Guard a “warning order,” which he described as “a heads up for folks.”

From Salon • Jan. 8, 2026

But wherever I go, I know I will feel most at home with the wounded of the world, who hold their heads up high no matter how broken they may seem.

From "Lucky Broken Girl" by Ruth Behar

From Roget's 21st Century Thesaurus, Third Edition Copyright © 2013 by the Philip Lief Group.