And what, this: Dom Perignon?

More from O'Brian:

'And having seen the parents I am impatient to see this youth, the fruit of their strangely unattractive loins: will he be a wretched mammothrept? A little corporal? Or will the resiliency of childhood...?'

'He will be the usual damned little nuisance, I dare say: but at least we shall know whether there is anything to be made of him by the time we are back from Alexandria. We are not saddled with him for the rest of the commission.'

Yes: mammothrept. Sounds worse than it is, by far.