Pounding a nail in at an angle tieing two boards together.  Probably called the same thing with a screw.

Michael Setunsky nailed it! 

Michael has it correct below

Tony and Suzanne Marriott, Associate Brokers Toenailing is securing a piece of lumber perpendicular to another and nailing it at an angle.

You're driving the point home that knowing construction terms is important.  

I could have some fun with this but the real answer is provided by Michael Setunsky!

You're suppose to keep your feet out of the way when using a nailgun.

That's what I need to do tonight to make my feet look better in sandals. 

securing a joint with an angled nail.

Some kind of custom pedicure, right?!

I would go with Ken Jones answer  guessing.

driving a nail or screw into a board at an angle....

Is it a group pedicure where everyone sits in a circle and clips the nails of the person to their right?

When your foot walks into a wall so hard that your toe swells up and the nail falls off.

That is when walking through a construction site we step on a freaking nail and send it through the bottom of our foot up through the toenail ... and then head to the ER. 

Something to do with carpentry, how boards are nailed to each other.

Oh this will get lots of creative answers but it applies to a technique generally used in trim carpentry to install a trim piece in a very tight spot.

I know now!

Michael has it right... unless your referring to a nail gun accident

Under the kitchen cabinets by the floor? or is that toe kick?

That is something Sandy does to me if I don't give her all my money...OUCH!

No idea.