Another word for sign

Answer 1

The word 'sign' is both a verb and a noun.
The noun 'sign' is a word for:

• something that suggests the presence or existence of something else;
  
• a trace or a vestige of something;
  
• a displayed structure that uses words to convey information;
  
• a posted notice;
  
• a figure or device that is a symbol in math or music;
  
• one of 12 divisions of the zodiac;
  
• a word for a thing.
  

The noun forms of the verb to sign are signer, signee, signitor, and the gerund, signing.
A related noun form is signature.

Example uses:

Noun: The sign said 'stop'.

Verb: Just sign on the bottom line and the car is yours.

Answer 2

Depends on what type of sign you mean.

A placard is a sign.

An omen is a sign.

Manual language is comprised of signs.

Answer 3

Sign is already a verb, as it can be used as an action.
For example: "we will sign the papers".

Some other verbs are signs, signing and signed.

Answer 4

omen