To "bind" a key on ones keyboard to preform a specific task when struck. Normally preformed in console baised PC games such as Counter-Strike. This is generally used to allow the player to say entire sentences with the stroke of 1 bound key.
Player brings up his console and types... bind \ "say LoL we pwned you wOoT!".
After this whenever the player strikes his \ key his character will say "LoL we pwned you wOoT" in his chat menu.
The action of hitting an opposing player in the head with 1 bullet wounding them greatly but not causing death.
Most communly used in first person shooter games and is used to relay the information that the opponant is hurt badly to your teammates.
Normally if you are close enough you can hear the sound which makes a lound "dink" hence the deffinition
"Oh man I didn't kill him but I dinked him to 10 hp."
"Go man rush him hard I dinked him already!"