Welly boot

Best definition
Welly boot
A term used for overly large vaginas. Refering to the popular wet weather rubber footwear, Wellington Boots. If a certain

level of skankiness is suspected custard can be added to the mix.

Her cunt is like a Welly Boot or Her cunt is like a Welly Boot full of custard.
Welly boot: define #2
Wellington boots, as adapted for quick conversation between immature morons such as myself.
‘I went out splashing in puddles today.’

‘Did you take your wellyboots?’

‘Why, yes I did.’