If you’d like to prevent Google from combining this potentially sensitive data with the information it has collected from your YouTube, Google+, and other Google accounts, you can remove your Web History and stop it from being recorded moving forward.
After signing into your Google account, choose Account Settings from the pull-down menu in the upper-right corner of a Google product such as Gmail, Google+, or Google.com. From the Account Settings page, scroll down to the Services header and click on the “Go to web history” link.) If your Web History is enabled, you’ll see a list of recent searches and sites visited. Click the gray Remove all Web History button at the top of the page and a subsequent OK button to clear your Web History.