Here you go, taken from Wickpedia:
Janner has an origin as a slang term referring to any English person born within ten miles of the sea. More specifically, a Janner is to Plymouth, as a Scouser is to Liverpool, or a Geordie is to Newcastle.
"Janner"1 is used as both noun and adjective, describing the accent and colloquialisms used by the people of Plymouth, in South-West Devon, United Kingdom. For example:
"ere bey, wheres that to?" hello friend...do you know the location or whereabouts of something?"
* "Yurtiz" translates to "Here it is".
* "fockin massiv, init beys?" translates to "Very large, isnt it friends?".
o "'Reeet meht" translates to "Hello dear friend, how have you been lately?"
o "Get on boss" translates to "There you go, friend".
However, with the changes in the local economy in Plymouth over the course of the 1980s and 1990s, from the Royal Navy being the major employer to being a university city housing a large number of students from outside the city, the term has developed an additional secondary pejorative sense describing the city's lower classes.
This leads to the term being used both pejoratively and normally by self-identification by all social classes within Plymouth. In this sense, whilst the middle classes and specifically students use it as a noun to denote the roguish elements from the rougher echelons of the city, natives still use the term proudly as a form of identity, featuring in many of the football team Plymouth Argyle supporters' chants.