Urban Dictionary: Definitions by solongandthanks..

mumcus

1. To cuss ones mum in a most derogatory fashion.
2.To describe a put-down of the worst kind: 'dude, that's such a mumcuss!'

1.e.g. 'your mum is so fat..'. 'your mum is so dumb..'

Similar to damn! Often used when the range of emotion/ rage you feel cannot be defined in just a singular expletive swearword.

'Dagnammit, i always miss these things!'

Mr Hasselhoff's official title. A term of respect when refering to 'the Hoff'

'May the Hoffmeister be with you'
'All hail the Hoffmeister'