caution vs sign

caution

noun
  • A yellow card. 

  • A formal warning given as an alternative to prosecution in minor cases. 

  • Security; guaranty; bail. 

  • Prudence when faced with, or when expecting to face, danger; care taken in order to avoid risk or harm. 

  • A careful attention to the probable effects of an act, in order that failure or harm may be avoided. 

verb
  • To warn; to alert, advise that caution is warranted. 

  • To give a yellow card 

sign

noun
  • An astrological sign. 

  • A specific gesture or motion used to communicate by those with speaking or hearing difficulties; now specifically, a linguistic unit in sign language equivalent to word in spoken languages. 

  • Sign language in general. 

  • A wonder; miracle; prodigy. 

  • A perceptible (e.g. visible) indication. 

  • A property of the body that indicates a disease and, unlike a symptom, can be detected objectively by someone other than the patient. 

  • A military emblem carried on a banner or standard. 

  • Physical evidence left by an animal. 

  • A clearly visible object, generally flat, bearing a short message in words or pictures. 

  • A semantic unit, something that conveys meaning or information (e.g. a word of written language); (linguistics, semiotics) a unit consisting of a signifier and a signified concept. (See sign (semiotics).) 

  • An omen. 

  • Positive or negative polarity, as denoted by the + or - sign. 

verb
  • To write (one's name) as a signature. 

  • To validate or ratify (a document) by writing one's signature on it. 

  • To communicate using gestures to (someone). 

  • To bless (someone or something) with the sign of the cross; to mark with the sign of the cross. 

  • To engage (a sports player, musician etc.) in a contract. 

  • To determine the sign of 

  • To cross oneself. 

  • To furnish (a road etc.) with signs. 

  • More generally, to write one's signature on (something) as a means of identification etc. 

  • To write one's signature. 

  • To finalise a contractual agreement to work for a given sports team, record label etc. 

  • To use sign language. 

  • To communicate or make known (a meaning, intention, etc.) by a sign. 

  • To calculate or derive whether a quantity has a positive or negative sign. 

  • To mark, to put or leave a mark on. 

  • To communicate using a gesture or signal. 

How often have the words caution and sign occurred in a corpus of books? (source: Google Ngram Viewer )