I know these are not just Dublin words, that is why the title of the video is "Dublin / Ireland" slang.
Arseways = "I did it all arseways" = I made a complete mess of it!
Deadly = awesome
Banjaxed = broken, no good
Bloody = strengthing adjective, used liberally
Brutal = terrible
Chips = french fries
Dosser = layabout, useless
Eejit = idiot
Gaff = house
Gawk = stare
How's the talent? = Is there anyone good looking about?
Kip, to have a = short sleep, nap
Knackered = very tired
Massive = brilliant, deadly