I've got a "haunch" someone will know ;)

Was that the guy with the bad back from Notre Dame?

a bracket to support an extra load....could be an extra ledge in a foundation to support a load ...

Something to take on extra weight or a heavy load.

I have one of those under my chair ... which carries an extra load. 

I do not know.

leg loin of an animal like a pretty lady's thighs, pig or something?

I have no idea. 

It is knowing whether or not a corner is square.  You either have a haunch or not...

A guess as said by someone with marbles in his mouth? 

You can sit on it

I remember this word from my days of horseback riding.  Can't remember the meaning though.  :(

Something to do with that Appraisal question up above?

A built in siting bench for me to rest my haunches?

Barbara Todaro has the answer. She is amazing!

I have not heard that term used. In the south we just say ledge.

That is when I think an outcome will turn out right.

It's the malady the "haunch back of Notre Dame" suffers from

Barbara Todaro knows these definitions inside - out and sideways too.  

Jennifer Mackay was first.  Otherwise, that was going to be my answer.  

Barbara Todaro said it much better that I planned to answer. Haunches are very useful on humans too!