Is there any way to remove an app from iTunes?

I cannot figure out how to delete my downloaded iPhone apps that appear in iTunes 11.3 running under 10.6.8 on my MacBook Pro.

I can remove them from my iPhone, which is good, but I went a little wild years ago trying out apps thinking I could delete the redundant ones once I had decided which ones I like. Well, I've decided, but the whole discard pile is still cluttering up my iTunes window. They also require lots of CPU time getting themselves updated.

Deleting them forever must be simple, but I've run through my gamut of ideas (hitting my keyboard's Delete button, and searching the pull-down menus) with no joy, so I though I'd ask:

What's the trick?

--Gil