Google Correlate is a tool that Google rolled out in 2011. It’s a close cousin to Google Trends – it’s actually Google Trends in reverse.

Google Correlate is a tool that Google rolled out in 2011. ... a tool on Google Trends which enables you to find queries with a similar pattern to a target data series. The target can either be a real-world trend that you provide (e.g., a data set of event counts over time) or a query that you enter.