Alice and Humpty Dumpty
a lovely example of Carroll's lexicological metaplay

From Chapter 6 of Through the Looking-Glass, in which Alice converses with Humpty Dumpty:

...there are three hundred and sixty-four days when you might get un-birthday presents—'

'Certainly,' said Alice.

'And only one for birthday presents, you know. There's glory for you!'

'I don't know what you mean by 'glory,'' Alice said.

Humpty Dumpty smiled contemptuously. 'Of course you don't—till I tell you. I meant 'there's a nice knock-down argument for you!''

'But 'glory' doesn't mean 'a nice knock-down argument,'' Alice objected.

'When I use a word,' Humpty Dumpty said in rather a scornful tone, 'it means just what I choose it to mean—neither more nor less.'

'The question is,' said Alice, 'whether you can make words mean so many different things.'

'The question is,' said Humpty Dumpty, 'which is to be master—that's all.'

Alice was too much puzzled to say anything, so after a minute Humpty Dumpty began again. 'They've a temper, some of them—particularly verbs, they're the proudest—adjectives you can do anything with, but not verbs—however, I can manage the whole lot of them! Impenetrability! That's what I say!'

'Would you tell me, please,' said Alice 'what that means?'

'Now you talk like a reasonable child,' said Humpty Dumpty, looking very much pleased. 'I meant by 'impenetrability' that we've had enough of that subject, and it would be just as well if you'd mention what you mean to do next, as I suppose you don't mean to stop here all the rest of your life.'

'That's a great deal to make one word mean,' Alice said in a thoughtful tone.

'When I make a word do a lot of work like that,' said Humpty Dumpty, 'I always pay it extra.'

'Oh!' said Alice. She was too much puzzled to make any other remark.

'Ah, you should see 'em come round me of a Saturday night,' Humpty Dumpty went on, wagging his head gravely from side to side: 'for to get their wages, you know.'

The version I've been carrying in mind and occasionally quoting is a happy conflation of two parts of Dumpty's discourse:

(of words) "I pays them extra and I makes them mean what I like" It turns out that the "make/makes them mean what I like" is widely quoted in the literature of Mathematics, where it first appeared in Whitehead's Introduction to Mathematics

...Not only the practical man, but also men of letters and philosophers have expressed their bewilderment at the devotion of mathematicians to mysterious entities which by their very name are confessed to be imaginary. At this point it may be useful to observe that a certain type of intellect is always worrying itself and others by discussion as to the applicability of technical terms. Are the incommensurable numbers properly called numbers ? Are the positive and negative numbers really numbers ? Are the imaginary numbers imaginary, and are they numbers? are types of such futile questions. Now, it cannot be too clearly understood that, in science, technical terms are names arbitrarily assigned, like Christian names to children. There can be no question of the names being right or wrong. They may be judicious or injudicious ; for they can sometimes be so arranged as to be easy to remember, or so as to suggest relevant and important ideas. But the essential principle involved was quite clearly enunciated in Wonderland to Alice by Humpty Dumpty, when he told her, a propos of his use of words,"I pay them extra and make them mean what I like." So we will not bother as to whether imaginary numbers are imaginary, or as to whether they are numbers, but will take the phrase as the arbitrary name of a certain mathematical idea, which we will now endeavour to make plain.