To be on the alert, to be vigilant; to be on one's guard against danger or surprise.

intransitive. To give heed, take care, be on one's guard. Const. of, with; to oneself; to and infinitive to do to ware: to inform, notify (const. of…

To be cautious or on one's guard, to be wary; to take care, take heed, in reference to a danger. simply.

To be on one's guard against some action or occurrence; to take care, beware (that…). intransitive or with object clause. Obsolete.

To take precautions, be watchful or cautious. In imperative: Take care, see to it that.

The action of watching. Obsolete. In phrases. at (the) wait, on the watch. to do, make wait, to keep watch. to have in wait, to have under…

The action of watching. Obsolete. In phrases. at (the) wait, on the watch. to do, make wait, to keep watch. to have in wait, to have under…

intransitive. To keep watch; to be alert or vigilant; to take care, be careful. Also in imperative, as a warning. Cf. lookout, n. 1.

intransitive. To direct one's sight in various directions in succession; to survey one's surroundings; to look here and there, let one's eyes…

To be or keep awake; to be vigilant, to watch. rare. (Cf. wake, v.)

intransitive. To watch carefully; to keep vigil.

to keep (also have) an eye (also one's eye, one's eyes) open (for) and variants: to be watchful or observant (for).

transitive. With it. To act the part of a sentinel perdu; to lie in ambush.

To keep watch vigilantly; to be on the lookout.

To remain awake, refrain from sleeping, keep watch or vigil; to remain alive. Obsolete. rare.

To keep a sharp look-out or watch; to take heed; to be on the look-out. Thieves' cant.

Acute or penetrating in intellect or perception. Hence of observation, an observer: Vigilant. Phrase, to keep a sharp look-out.

Used in figurative phrases, such as to keep one's weather-eye open, to be watchful and alert, keep one's wits about one.

Originally U.S. to keep (also have) an eye out: to be very alert or watchful. Also with modifying word as sharp, weather, etc. Frequently with for…

colloquial (originally U.S.). to keep one's eyes peeled and variants: to remain alert, be on the lookout; to watch carefully for. Cf. to keep one's e…

to watch out (colloquial, originally U.S.): to look out, to be on one's guard.

U.S. colloquial. to skin one's eyes: to remain alert, be on the lookout. Cf. to keep one's eyes skinned at skinned, adj. phrases.

to have (also keep) one's eye on the ball: to be, or to remain, alert.

colloquial (originally U.S.). to watch one's back: to be on one's guard; to be alert to a possible (physical) threat to oneself (sometimes…