Can be used as an
intensifier / for emphasis, or meaning 'completely' / 'thoroughly' / 'totally' combined with adjectives. Probably used only in London and parts of the South East of England.
“That was a
proper good arse-kicking mate. Let's go to the pub and get a pint to celebrate.”
Note: The equivalent in the North of England is 'well', as in “We're
well fucked now” meaning completely / totally / 100% fucked, i.e. in trouble / danger or we have no options after something has gone wrong. Another example (N. England only) “she was well pissed" (with stress in 'well') meaning she was very drunk. (Important: never meaning “angry" in Britain as in the US, although England does have the common “(be) pissed-off" meaning “mildly annoyed” and "Piss off!" meaning "go away!").