Radio communication dates back to the late 1800s and is still in use today. While there have been some changes and improvements to the technology over the years, directional couplers and other equipment are still in use, and you still have to tune to the right frequency or amplitude to send and receive messages. Radio communication is used by military, law enforcement, and first responders to coordinate efforts. Sometimes it can save lives.

Users of any communication technology come up with their own slang and shorthand to communicate more effectively. Radio communication is no exception. You may be familiar with radio lingo if you watch a lot of movies or television. You’ve probably figured out what they mean from context. Maybe you even use some of these terms in your own life. However, you might not know how or why they came to be in use.

“Over” and “Out”

With some types of radios, you cannot receive a message if you are trying to send one at the same time. If two people try to speak at the same time, neither will be able to hear each other. Radio operators need a way to signal to one another that they are finished talking and ready to hear a response and say the word “over” to signify this to the other party.

When a person is ready to sign off and discontinue the conversation, he or she says “out.” That signals to the other person that the first person is no longer available to listen to any more messages for the time being.

“Wilco”

Many radio terms are shortened versions of longer phrases. “Wilco” is a good example of this. It’s a shortened version of the phrase “will comply.” If the person with whom you are communicating by radio asks you to do something, you could respond with “wilco” to let the other person know that you understand their request and intend to carry it out.

“Mayday”

The term “mayday” is used to ask for aid in a life-threatening situation. It has nothing to do with the first day of the month of May, although the two go by the same name. Actually, “mayday” is an English phonetic spelling of the French phrase “m’aidez,” which literally means “help me.”

“Roger”

In radio lingo, “roger” is kind of similar to “wilco.” There may be some overlap between the two, or you may use them in combination. While “wilco” means that you intend to do something, “roger” only means that you understand. “Roger” was adopted by the U.S. military and it relates to a custom in Morse code communication that used the letter R to signify a message received.