Discussions of Hobbes’s views about language seem to proceed on two separate paths. (Neither of these paths is terribly busy, I’ll grant you, but they both seem to be there.) On the one hand there are discussions of Hobbes’s general philosophy of language — signification, nominalism, and the like. On the other hand there are discussions of what Hobbes says about language in his moral and political philosophy — on what he says about ‘good’ and ‘evil’, for example. But it seems to me that these two discussions should be more closely tied together.
One interesting text for starting to think about the link between the two is the final paragraph of chapter 4 of Leviathan. There Hobbes discusses moral language, including the names of virtues and vices. This discussion contributes to the moral and political projects of the book, while also being part of a general account of the workings of language. It uses the terminology of that general account, in particular its notion of signification.
The names of virtue and vices, and others like them, are, Hobbes says, of “inconstant signification”. Moreover, they are words,
which besides the signification of what we imagine of their nature, have a signification also of the nature, disposition, and interest of the speaker; such as are the names of Vertues, and Vices; For one man calleth Wisdome, what another calleth feare; and one cruelty, what another justice; one prodigality, what another magnanimity; and one gravity, what another stupidity, &c. And therefore such names can never be true grounds of any ratiocination. No more can Metaphors, and Tropes of speech: but these are less dangerous, because they profess their inconstancy; which the other do not.