Definitions

on the lookout

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 heads up heedful on guard on one's toes on the ball on the job 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

attentive

Synonyms

STRONGEST

aware conscientious interested observant vigilant watchful

STRONG

heedful

WEAK

alert all ears awake enrapt enthralled fascinated glued hanging on every word hooked immersed intent listening mindful on one's toes on the ball on the job on the qui vive preoccupied regardful studious

Antonyms

STRONGEST

careless inattentive negligent unaware

WEAK

disregarding heedless ignorant inconsiderate neglectful neglecting unattentive

ADJECTIVE

cautious

Synonyms

STRONGEST

circumspect discreet judicious leery prudent tentative vigilant wary watchful

STRONG

alert safe

WEAK

all ears cagey calculating chary considerate forethoughtful gingerly hedging one's bets heedful keeping on one's toes playing it cool playing safe politic provident pussyfoot shrewd taking it easy taking it slow thinking twice walking on eggs watching one's step watching out with one's eyes peeled

Antonyms

STRONGEST

careless certain foolish inattentive incautious indiscreet negligent rash reckless sure thoughtless uncareful unwise

WEAK

hasty heedless imprudent unguarded unobservant

ADJECTIVE

guarded

Synonyms

STRONGEST

cautious circumspect reserved restrained

STRONG

calculating

WEAK

attentive cagey canny careful chary discreet gingerly leery noncommittal overcareful overcautious prudent reticent safe vigilant wary watchful with eyes peeled

Antonyms

STRONGEST

bold careless extroverted incautious outgoing rash uncareful

WEAK

unguarded unsuspicious unwatchful

ADJECTIVE

on one's guard

Synonyms

WEAK

alert careful cautious defensive guarded heedful mindful observant on guard on one's toes on the watch upon one's guard vigilant watchful

ADJECTIVE

on the ball

Synonyms

WEAK

active all ears attentive bright cagey careful clever good hands heads up intelligent lively observant on guard on one's toes on the job 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 heads up heedful hip intelligent jazzed observant on guard on one's toes on the ball on the job on the qui vive perceptive psyched-up quick ready sharp spirited switched on vigilant wakeful wary watchful wide-awake wired wise with it

ADJECTIVE

politic

Synonyms

WEAK

adroit advisable canny cool delicate diplomatic discreet expedient in one's best interests judicious perspicacious prudent sagacious sensible sharp shrewd smooth tactical tuned-in urbane

Antonyms

WEAK

impolitic indiscreet injudicious tactless unwise

ADJECTIVE

unsleeping

Synonyms

WEAK

alive astir attentive awake careful heedful insomniac insomnious observant on guard on the alert on the qui vive sleepless vigilant waking wary watchful wide-awake

ADJECTIVE

vigilant

Synonyms

STRONGEST

anxious attentive aware cautious circumspect keen observant wary

WEAK

acute agog alert guarded looking for looking to on alert on guard on the ball on the job on the qui vive on toes open-eyed sharp sleepless unsleeping waiting on wakeful wide-awake with eyes peeled with weather eye open

Antonyms

STRONGEST

careless heedless ignorant inattentive incautious indifferent indiscreet rash thoughtless unaware uncareful unobservant

WEAK

impulsive negligent

ADJECTIVE

wakeful

Synonyms

WEAK

alive astir attentive careful heedful insomniac insomnious observant on guard on the alert on the qui vive sleepless unsleeping vigilant waking wary watchful wide-awake

Antonyms

WEAK

sleepy unaware

ADJECTIVE

wary

Synonyms

STRONGEST

attentive circumspect considerate distrustful frugal leery prudent suspicious vigilant watchful

WEAK

alert cagey calculating canny chary discreet doubting gingerly guarded handling with kid gloves heedful keeping on one's toes on guard on the qui vive provident safe saving sly sparing thinking twice thrifty unwasteful walking on eggs watching one's step watching out wide-awake

Antonyms

STRONGEST

careless certain inattentive incautious inconsiderate indiscreet negligent

WEAK

foolish heedless rash reckless

ADJECTIVE

wide-awake

Synonyms

WEAK

active alert all ears attentive bright bright-eyed and bushy-tailed fast on the draw heads up intelligent lively on guard on one's toes on the ball on the job psyched-up quick ready sharp spirited vigilant watchful wide-eyed wired

ADVERB

on guard

Synonyms

WEAK

alert careful cautious defensive guarded heedful mindful observant on one's guard on one's toes on the watch vigilant wary watchful

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.

Still, investors should be on the lookout for any recommendations regarding the maintenance and operation of Boeing’s flagship 787 jet.

From Barron's • Jun. 8, 2026

In the future, she is hopeful for more projects like this one and says they are on the lookout for some more land.

From BBC • May 25, 2026

According to recordings of dispatch audio from San Diego police reviewed by The Times, dispatchers told officers in the field at approximately 11:05 a.m. to be on the lookout for a “possible terroristic threat.”

From Los Angeles Times • May 22, 2026

Just be on the lookout in case your device or browser needs your permission to update and reboot.

From The Wall Street Journal • Apr. 19, 2026

He knew the importance of collecting data and finding new markets; he was always on the lookout for better management strategies.

From "Freakonomics: A Rogue Economist Explores the Hidden Side of Everything" by Steven D. Levitt

on the lookout

Example Sentences

Related Words