Safe-words (also spelled as safeword or safe word) are words that are used by the submissive partner to indicate distress. Usually the use of a safe-word means that the dominant partner stops whatever he’s doing. Some couples prefer having multiple safe-words to indicate varying levels of distress, i.e. one to slow down, one to stop completely.
A good safe-word is a word that is easy to pronounce and usually does not come up in a scene. Words like “Stop” or “No” do not make good safe-words since they can also be used in simulated struggle. Some common safe-words include “mother” and “red”.