Redakto: My contesting of the old usage here has been successful.
Originala: Since when does Cetere mean "by the way"?
Zaminhof, in his first book gives us: ceter' the remainder, the following, rest
Butler gives us a series of similar translations, none of which are "by the way".
In the PIV I found: CETERA
Restanta, ankoraŭ ne menciita:
La asocio plibonigu la fluon de informoj inter la membroj, la landaj asocioj, la komitato, la estraro, C.O. kaj ceteraj instancoj ligitaj al UEA.
Cetere, ĉu vi scias, ke ŝi jam havas bebon?
Faru vian aferon, Dio zorgos ceteron.
I am contesting this definition.
I don't know since when, but it certainly means that. It is an idiomatic way to express the same idea as "by the way", even if it has a different literal meaning. (And to all dictionary citers: I'm not arguing about what's in the dictionary; I'm just saying that in practice "cetere" is what many Esperantists use when English speakers would say "by the way".)
As there seems to be some confusion about the difference between cetere (besides) and parenteze (by the way), here is a little dialogue that gives a context to the sentence and might make the distinction clearer:
- Vi vere devus helpi min serĉi mian hundon. Cetere, kion vi manĝas?
- Ne estas mia kulpo se vi mismetas vian bongustan hundaĉon. Parenteze, ĉu vi volas iom?
Or in English:
- You should really help me search for my dog. Besides, what are you eating?
- It's not my fault if you mislay your tasty mutt. By the way, do you want some?
The two adverbs cannot be switched. In the first line, "what are you eating?" isn't so much a question as an additional reproach. The speaker could also have said: "Why are you eating disgusting raw meat instead of helping me?" The speaker isn't really changing the topic, and it would make no sense to frame this as a casual afterthought. In the second line, the speaker could instead say "Besides, that's precisely what I'm eating" to stress how the two topics are related. Instead, he chooses to casually invite his interlocutor to partake of the spoils of his crime without making it too obvious what's going on. Here, as is almost always the case with invitations, besides wouldn't make much sense.
Besides means: in addition to that, more importantly, however, you must admit, an item on the side but closely related and ignorantly or unreasonably or actually deceitfully overlooked by you, I wish to draw your attention to this even more important consideration. Borderline aggressive. By the way means: if I may change the subject, on another matter, this is not really related, but, on the way we are passing something unrelated but since I am here with you may I point it out... . Slightly apologetic. Examples. Don't drink it. It's horrible wine - besides, you are already drunk. Don't drink it. It's horrible wine - by the way, you can have water if you prefer it.