One of those slap your forehead moments when you realise that you've just done something incredibly stupid.
The moment when something "dawns on you" and "the penny drops.
> A dohment is when you realise that you've put the baby outside and tucked the cat up in the cot for the night.
> or
> A dohment is when you wonder why the lawn isn't looking any better then notice that you haven't engaged the lawnmower blade.
