What is a steering knuckle?

[HISS GT]

Years ago my car was in an accident and just recently I found out that the reason my front tire is toed-in is that I need a new strut and steering knuckle. The I took it to wanted too much so I was going to buy the stuff myself but I can't find a steering knuckle. What is it this part, how much is it and where can I find one?

 

[jrichker]

The steering knuckle is the part of the spindle the tie rod end bolts to. On some cars it was a separate part that bolts to the spindle, and was replaceable.