Looking at the names in the poll (rather than just the total numbers, because the un-named votes can be cheated):
65 posters understand “campaign” to mean a series of adventures undertaken by a group of PCs.
3 posters understand “campaign” to mean the world setting for a game.
15 posters understand “campaign” to mean something else – reading the “something else” explanations, most seem, to me, to split hairs right down the middle between the two definitions. Some even seem to be just subtle rewordings of the majority definition.
Now, we could all look at this and consider that when using the term, “campaign,” in this forum, if you don’t mean a series of adventures undertaken by a group of PCs, you probably should explain your different intent in your post. And when you read the term, “campaign,” in this forum, you probably should read it as a series of adventures undertaken by a group of PCs unless the poster specifically explained differently. Because this is how the vast majority of readers and posters here understand the term.
This doesn’t mean that the minority definition is wrong, or dumb, nor that it should be discarded and never used. It just means that there is a distinct definition that the vast majority of posters here understand for this term. Using the term for a different meaning, without explanation, is not conducive to understanding discourse.
Although, I have no illusion that there won’t be someone(s) who will insist on using and reading the term in their own preferred definition, without explanation, much to the confusion and consternation of other posters.
Bullgrit