I have faced this error in the past. To fix it there are multiple options just check which one suits to your code.
In your inspect element where you have encountered the error is printed you need to just hover with your mouse on your filename and it will give you the complete path of file.
After doing this just open your Jquery easing plugin file and simply wrap the code inside as shown below:
Your Code goes here...
You should also check if you are loading the jQuery more than once. If by mistake you have inserted in your footer manually then just try removing it.
If you are importing a jQuery easing plugin or it is higher than 1.7.2 then you must remove that and simply use below code:
Hope it fixes your issue.