You've spelled it correctly. Pinioning a bird's wings is a process where (usually when the bird is only days old, without benefit of an anesthetic) you take a tool such as toenail clippers or scissors and cut off the first few flight feathers--not just the feathers but the cuticle. It's an amputation and is permanent, and should only be done by a vet or someone VERY experienced. Pinioning is done so that the feathers never grow, rendering the bird flightless or nearly so. It's kind of like clipping off the ends of your fingers so your fingernails won't grow. People do this so that their birds cannot fly away.

I personally think it's a nasty thing to do to a bird, especially migratory birds that will one day have an irresistable urge to migrate and will be unable to do so.

I'm sure if you do a Google search you will come up with all kinds of info on pinioning, here's one:

http://www.gamebird.com/pinioning.html

Velvet ~:>

You dont pay 500 for a pair of birds with out wings pinioned,theyll leave.You dont need anestetic at a few days its not even bone.Its usually bloodless at a few days old.It can also be done when older.You use then anestetic and blood stop.Put them in an area when you can watch to make sure bleeding stopped.On a swan its the extra tip that sticks out on end of wing.You can alsotrim flight feathers but youll have to keep up with that so they dont grow back.