COMMON If you err on the side of caution, you decide to act in a careful way, rather than take risks. It is better on your first few weights sessions to err on the side of caution, and start with a weight which is lighter than you think you can handle. Note: People use other words instead of caution, according to the subject they are discussing. When I discussed the matter with ministers in July I said that we should err on the side of generosity.