Diggi is another version of "digga", which can be either used as an alternative to bro/dude/mate or to express how you feel about the current situation. Diggi is often used by soft/wholesome/cute people.
Diggi i fucking love you
A frantic dance a Geordie does when he has held it in too long. This usually occurs after one too many brown ales and a failure to visit the water fall grotto before leaving the pub or when small children have a sudden need to go.
(Mam) ..."Tommy is doing a diggy dance. Best get him to the toilet before he wets his pants!"