mindmap root((标志)) sign is applicable to any means by which one conveys information without verbal communication: made a ~ to the others to wait while he reconnoitered. signal usually applies to a conventional and readily recognizable sign that conveys a command, a direction, or a warning: saw the coach's ~; or it may apply to a mechanical device that performs a comparable function: waiting for a traffic ~ to change to green. sign applies to any indication to be perceived by the senses or the reason: interpreted her smile as a good ~. mark suggests something impressed on or inherently characteristic of a thing often in contrast to something outwardly evident: the bitter experience left its ~ on him. token applies to something that serves as proof or offers evidence of something intangible: this gift is a ~ of our esteem. note suggests a distinguishing mark or characteristic: a ~ of despair pervades her poetry. symptom suggests detectable outward indication of an internal change or abnormal condition: rampant violence is a ~ of that country's decline.