In “Old words, new meanings,” I talked a little about how words can come to occupy semantic niches; really, this is just the question of how words can come to express the meanings that they express. The idea is that this is a microeconomics phenomenon; populations give value to words by using them to mean something, so meaning is a kind of emergent property of language use in a population.
Of course there’s more—a lot more—that needs to be said here, but I want to focus on the problem of “entrenchment” that I raised in the earlier post. Entrenchment is a complex phenomenon, one that helps fix the language as a social medium, and I think you can look at it from a number of different perspectives. Right now, I want to think about the choice that speakers had when trying to express the new social relationship, establish a Facebook friendship.
We can assume that, at some point, speakers were faced with a choice between at least two forms to express the meaning establish a Facebook friendship: They could verb a noun—that is, they could use the noun friend as a verb—-or they could extend the old form befriend into a new semantic domain, one that is presumably adjacent to its fixed meaning.
Notice that friend as a noun doesn’t express the right relationship; a Facebook friend is not necessarily a friend in real life. But the meaning that friend as a verb would express (had it existed) is already expressed by the old form, befriend.
At this point, strategic reasoning can take over. The speaker can reason that if she uses befriend, then the odds are that the hearer will take her as meaning the old concept of become friends which is not what she intends to signal. In other words, befriend is entrenched in that meaning.
If the speaker uses friend, however, the hearer can infer that she must not have meant become friends; had she meant that, then she would have been more likely to use befriend (although there is always the possibility of error—perhaps she couldn’t “find” befriend in her mental lexicon). Friend as a verb does not have an entrenched meaning, but its noun use is in a nearby semantic niche, so (presumably) friend as a verb can now occupy the new semantic niche of establish a Facebook friendship.
As I mentioned, there’s another perspective to take here. Befriend had to become entrenched in the sense of make friends. In particular, it had to occupy the make friends niche with such tenacity that friend as a verb could not invade that niche and drive it out. It has to be the case that, originally, befriend was the grammatically regular way creating a form that meant become friends; verbing the noun friend was blocked. As the use of the prefix be- declined, it would have to be that the frequency of befriend remained high enough to drive out competitors.
This is one of the other senses of “entrenchment.” It’s very similar to the sense of entrenchment that Nelson Goodman was talking about in his book Fact, Fiction and Forecast. Once a term is entrenched in a semantic niche, it becomes difficult for a new form to drive it out of the niche.
Notice, though, that strategic reasoning lies at the heart of the whole process.