sign

1. Something that suggests the presence or existence of a fact, condition, or quality.
2.
a. An act or gesture used to convey an idea, a desire, information, or a command: gave the go-ahead sign.
b. Sign language.
3.
a. A displayed structure bearing lettering or symbols, used to identify or advertise a place of business: a motel with a flashing neon sign outside.
b. A posted notice bearing a designation, direction, or command: an EXIT sign above a door; a traffic sign.
4. A conventional figure or device that stands for a word, phrase, or operation; a symbol, as in mathematics or in musical notation.
5. pl. sign An indicator, such as a dropping or footprint, of the trail of an animal: looking for deer sign.
6. A trace or vestige: no sign of life.
7. A portentous incident or event; a presage: took the eclipse as a sign from God.
8. A body manifestation that serves to indicate the presence of malfunction or disease.
9. One of the 12 divisions of the zodiac, each named for a constellation and represented by a symbol.