caution

Etymology

Recorded since 1297 as Middle English caucioun (“bail, guarantee, pledge”), from Old French caution (“security, surety”), itself from Latin cautiō, from cautus, past participle of caveō, cavēre (“be on one's guard”).

noun

1. Prudence when faced with, or when expecting to face, danger; care taken in order to avoid risk or harm.
   take caution
   have caution
   exercise great caution
   utmost caution is required when travelling in this dangerous neighbourhood
   act with caution
   … and on the Saturday heavy seas pounded the W.R. on its exposed coastal stretch between Dawlish and Teignmouth, loosening the ballast and forcing trains to proceed with extreme caution. 1960 December, “Talking of Trains: The railways and the Devon floods”, in Trains Illustrated, page 709
2. A careful attention to the probable effects of an act, in order that failure or harm may be avoided.
   The guideline expressed caution against excessive radiographic imaging.
3. Security; guaranty; bail.
4. (dated) One who draws attention or causes astonishment by their behaviour.
   Oh, that boy, he's a caution! He does make me laugh.
5. (law) A formal warning given as an alternative to prosecution in minor cases.
6. (soccer) A yellow card.

verb

1. (transitive) To warn; to alert, advise that caution is warranted.
2. (soccer) To give a yellow card