off: UK slang?

[Ted Jackson jr.]

> > I'm chuffed,
> > P.S. We did it!  Another boc-l project succeeds!
>
> Hooray!  And I just completed the last copy of the last tape for US
> Contributors!!
>
> So, what's next, the MM poetry book? >-)
>
> Allan.
>
Just curious as to the meaning of 'Chuffed?'  I seem to remember
Falstaff calling the victims of his raiding party 'ye fat chuffes.'
What is a chuff, and what is being chuffed?
theo