COMMON If you get a fix on someone or something, you get a clear idea or understanding of them. It's difficult to get a fix on what brokers earn. Their commissions depend on the number and cost of the properties they sell. His foreign policy adviser travelled to Washington to try to get a fix on US thinking. Note: You can also say that someone has a fix on someone or something if they understand them well. Do you have a fix on what the market wants? Note: This expression literally means to find out exactly where something is, usually by using radar or electronic equipment.