Hi aokh,
I'm afraid I can't really give any more examples of my use of "ku", other than the one I gave. (Or if I did, I don't think they would really throw much more light on the situation.) I'm pretty sure it's the same word / character as yours.
I find that it's the case that Chinese will usually introduce a "disambiguator", if two words sound exactly the same, and could be used in a very similar context. For example, "louse" and "lion" are pronounced the same in Mandarin. This could be confusing if one said "zai wo de wo fang li you yi zhi hen wei xian de shi". [Here I'm trying to say "there's a dangerous louse/lion in my bedroom", please excuse me if my Mandarin is not correct or idiomatic.] But (if I understand correctly), "lion" is
獅子 whereas "louse" is just
虱. [This has always struck me as amusing, because a
虱 is much smaller than a
獅子 .] Anyway, my point is that two identical syllables, roughly occupying the same grammatical and semantic space will quickly need to be disambiguated, and Chinese does do this. As my "ku" doesn't have a disambiguator, and neither does yours, I imagine that they are just the same "syllable/character".
So, I imagine that either: 1) I have just picked up the "wrong interpretation" of the meaning of the word, and have been misusing it all my life, or 2) There is some sub-community of Hokkiens who use it in this slightly different meaning, but that many Hokkiens just use it identically to the way Mandarin speakers use it. If the latter is the case, then it could well be the case that when a member of each of the two groups meet, they could each use the word in the way they are used to, without the other noticing, because there would be very few situations where the difference between it being "a few sentences" and "a few syllables" makes such a crucial difference that one of them would realise that the other was trying to express something different than the first person originally thought.
That's why I'd love to hear from other native Penang Hokkien speakers.