1. (noun) a signal that involves visual communication

• air sock
• air-sleeve
• drogue
• sock
• wind cone
• wind sleeve
• wind sock
• windsock
• armband
• barber's pole
• beacon
• beacon fire
• blinker
• trafficator
• turn indicator
• turn signal
• brake light
• stoplight
• flag
• signal flag
• flare
• flash
• light
• post
• stake
• red light
• warning light
• rocket
• skyrocket
• watch fire

1. (noun) a signal that involves visual communication

• sign
• signal
• signaling