I don't know what it means--but I don't think people ought to call a Lord such names.
As he passed us he said, 'Ruin of the country, sir! Fatal error, fatal error!' And then we looked back and saw he was getting quite near where Pincher was, and Alice and H.O.We walked on--so that he shouldn't think we were looking--and in a minute we heard Pincher's bark, and then nothing for a bit; and then we looked round, and sure enough good old Pincher had got Lord Tottenham by the trouser leg and was holding on like billy-ho, so we started to run.
Lord Tottenham had got his collar half off--it was sticking out sideways under his ear--and he was shouting, 'Help, help, murder!' exactly as if some one had explained to him beforehand what he was to do.

Pincher was growling and snarling and holding on.

When we got to him I stopped and said-- 'Dicky, we must rescue this good old man.' Lord Tottenham roared in his fury, 'Good old man be--' something or othered.

'Call the dog off.' So Oswald said, 'It is a dangerous task--but who would hesitate to do an act of true bravery ?' And all the while Pincher was worrying and snarling, and Lord Tottenham shouting to us to get the dog away.

He was dancing about in the road with Pincher hanging on like grim death; and his collar flapping about, where it was undone.
Then Noel said, 'Haste, ere yet it be too late.' So I said to Lord Tottenham-- 'Stand still, aged sir, and I will endeavour to alleviate your distress.' He stood still, and I stooped down and caught hold of Pincher and whispered, 'Drop it, sir; drop it!' So then Pincher dropped it, and Lord Tottenham fastened his collar again--he never does change it if there's any one looking--and he said-- 'I'm much obliged, I'm sure.