Performance and javascript issue in a drupal 7 website
You could try advagg, but shoving cloudflare at the problem is usually easier, let them deal with the js complexity by converting it to rocketscript for you for free!

Or you could mention which modules you have, how many scripts you are attempting to load, whether they are asynchronous/deferred etc, what version of jQuery, perhaps even a link to the site itself so we can have a look?