alert
     adj 1: very attentive or observant; "an alert and responsive baby
            is a joy"; "caught by a couple of alert cops"; "alert
            enough to spot the opportunity when it came";
            "constantly alert and vigilant, like a sentinel on
            duty" [ant: {unalert}]
     2: mentally responsive; "an alert mind"
     3: not unconscious; especially having become conscious; "the
        patient is now awake and alert" [syn: {awake(p)}]
     4: (usually followed by `to') showing acute awareness; mentally
        perceptive; "alert to the problems"; "alive to what is
        going on"; "awake to the dangers of her situation"; "was
        now awake to the reality of his predicament" [syn: {alive(p)},
         {awake(p)}]
     n 1: condition of heightened watchfulness or preparation for
          action; "bombers were put on alert during the crisis"
          [syn: {qui vive}]
     2: a warning serves to make you more alert to danger [syn: {alerting}]
     3: an automatic signal (usually a sound) warning of danger
        [syn: {alarm}, {warning signal}, {alarum}]
     v : warn or arouse to a sense of danger or call to a state of
         preparedness; "The empty house alarmed him"; "We alerted
         the new neighbors to the high rate of burglaries" [syn: {alarm}]
Source: WordNet® 2.0