The apex of a dong when mapped as a 2D mathematical graph. When extrapolated, the turning point is defined as the Dongpoint.
Alternatively, it can be characterised as a deeply philosophical question some penises ask upon ejaculation. Normally, he questions the creation of the universe or is seen riding the existential roundabout.
'Sir, I have found the Dongpoint on this particular graaph'
'Chuffing good work Porter!'
'Derek! Your penis makes me think too much during sex!'
Someone or something that bites your ankles.
To a postman, an ankle biter is often known as a dog.
To an adult, an ankle biter may be a toddler.
To hikers, an ankle biter is sometimes a tick.
And so on.