A very very good friend. A Diamond Geezer.
Familiarity and warmth to the friend in question can be added by extending the syllables.
Derived from the over-pronounciation of Geezer in any south-london native tongue. Heavy expression on the first syllable married with a strong pronounciation of the second syllable said in much the same was as the French say 'heur'.
1. Whats thee drinkin' cheesheur?
2. Mine's a JD n coke, thank thee chezzer.