Getting This Error: jQuery.easing[jQuery.easing.def] is not a function

[MaineWeb]

I have a WordPress Multi-Site setup. The blogs are using, for the most part, all the same plugins (I also tried disabling them and the error remained) and they are all using the same theme. All of them work great, except one. On this one, the slider doesn't function properly, and Firebug reveals some kind of jQuery error. The trouble is, I don't know what it means or how to fix it. Ideas?

Here's the site that is returning the error: http://fairfax.myhomecareblog.com/
Here's one of the dozen or so sites that is working: http://manhattan.myhomecareblog.com/

The slider should scroll through the full-sized photos. If I click on one of the thumbnails, the URL changes to something like this: http://fairfax.myhomecareblog.com/#fragment-2

[MaineWeb]

I tried deleting a referenced jQuery.js file from my theme. That didn't help. I'm grasping at straws, obviously! Started converting another blog on the same setup to the new theme and it is having the same problem as the Fairfax blog.

[MaineWeb]

Problem solved. It was a plugin that was activated but not set to be used - Slick Social Share Buttons.