Margin of safety refers to the amount by which something exceeds its minimum required level of safety. There are several synonyms for this term that you can use to convey the same message. These include cushion, buffer, leeway, security, and tolerance. All these words connote the idea of having an extra amount of something to ensure safety or success. For instance, if you say that an investment has a margin of safety, you imply that there is a cushion of protection in case anything goes wrong with the investment. Similarly, if you say that a building has a margin of safety, you mean that there is a buffer of safety measures that can protect it from any mishap.