Throughout the whole of Japan, there are countless ways of telling others to be quiet or that they're being a nuisance, as can be seen in JLect's category on Annoyance . Two of them that stand out, however, are the Kyushu expressions せからしか sekarashika and やじょらしか yajorashika, and their numerous variations:
Ignoring the adjectival ending -ka or -i, the main recurring theme is that both terms incorporate the suffix -rashi-, which functions more or less like the suffix "-like" in English. For example, 女らしい onna-rashii could be translated as "ladylike" or "womanly". Thus, given that it turns another word into an adjective, we would expect the roots seka- and yajo- (or variants thereof) to be connected to something else. But what could they be related to?
After a doing a search in a standard Japanese dictionary, I happened to come up with the following two possibilities that are semantically related:
- せいか【生家】 "one's parents' home"
- やじょう【耶嬢】 "father and mother"
Could it be possible that both expressions allude to one's parents or parents' home? And thus, by saying sekarashika or yajorashika, one would literally be telling another that they're "acting like (one's) parents"? It's an interesting possibility and I don't think it's impossible if we were to assume a semantic shift from "bossy/demanding"or "always yammering" to "annoying".