noun

1. something that indicates a fact, quality, etc.; indication; token black as a sign of mourning
2. 1. a gesture or motion that conveys information, gives a command, etc. a nod as a sign of approval
   2. any of the gestures used in sign language
   3. sign language (sense )
3. a mark or symbol having an accepted and specific meaning, as the sign ¢ for cent(s)
4. any linguistic unit, as a word, letter, etc., that is the symbol of an idea, function, etc.
5. a publicly displayed board, placard, etc. bearing information, advertising, a warning, etc.
6. ☆ anything marking the trail of an animal, as footprints
7. any visible trace or indication the signs of spring
8. 1. an act or happening regarded as a manifestation of divine will or power
   2. an omen; portent
9. sign of the zodiac
10. Med. an objective indication or symptom of a disease

Etymology: ME signe < OFr < L signum, a mark, token, prob. < base of secare, to cut (see saw): orig. sense prob. “incised mark”

transitive verb

1. to mark with a sign, esp. with the sign of the cross, as in blessing
2. to write one's name on, as in acknowledging authorship, authorizing action, etc.
3. to write (one's name) as a signature
4. to engage by written contract; sign on
5. Now Rare to indicate or express by a sign; signal
6. to communicate (thoughts, ideas, etc.) by using the sign language of the deaf

intransitive verb

1. to write one's signature, as in attesting or confirming something
2. to make a sign; signal; also, specif., to use the sign language of the deaf