condition of heightened watchfulness or preparation for action; "bombers were put on alert during the crisis"
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"
(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"
not unconscious; especially having become conscious; "the patient is now awake and alert"
eellike aquatic North American salamander with small forelimbs and no hind limbs; have permanent external gills
an acoustic device producing a loud often wailing sound as a signal or warning
a warning signal that is a loud wailing sound
a sea nymph (part woman and part bird) supposed to lure sailors to destruction on the rocks where the nymphs lived; "Odysseus ordered his crew to plug their ears so they would not hear the Siren's fatal song"
a cavity or passage in a tubular organ; "the lumen of the intestine"
a unit of luminous flux equal to the amount of light given out through a solid angle of 1 steradian by a point source of 1 candela intensity radiating uniformly in all directions
having little or no weight or apparent gravitational pull; light; "floating freely in a weightless condition"; "a baby bat...fluffy and weightless as a moth"; "jackets made of a weightless polyester fabric"
the basic unit of luminous intensity adopted under the Systeme International d'Unites; equal to 1/60 of the luminous intensity per square centimeter of a black body radiating at the temperature of 2,046 degrees Kelvin
examine eggs for freshness by holding them against a light