Originated on behalf of a certain anti-chav site, used to describe the odd relationship apparently inbred chavs
have with other (female) members of their family.
Like it's male counterpart bruncledad
, it derives from sister, aunty, and mum, with those terms being the female form of the words that make up the term bruncledad.
Again, with this defenition, no-one has been able to figure out how it is possible for a single female relative to be all of these things at the same time to the same person.
Whether or not this will become a suitably humourous counterpart to the word bruncledad is yet to be decided.
It is also worth noting that the word sounds a lot like chrysanthemum
He's just received his first giro. His sisauntymum must be so proud.