means the same thing as "Thank you", only abbreviated (has an appealing sound to the ear)
Waiter: "Would you like more tea ma'am?"
You: "Yes, thanka."
A combination of the word Thanks and Wanker.
Can be used when talking to your boss or somebody else who seems to be getting on your nerves.
"Hey boss thanka for that letter you sent me"
"Oh why thanka"
" Your such a good thanka"
" you ducking thanka"