vocabulary - Nuances between the different kanji spellings of あける：明 ける vs. 開ける vs. 空ける

開ける, 明ける and 空ける are all read as あける.

From their kanji, it is obvious that 開ける has to do more with opening (a door etc), 明ける with dawning and 空ける with emptying...

However, JMDict gives the exact same senses for all three of them (in fact, lists them as the same word):

開ける(P); 空ける(P); 明ける(P) 【あける】 (v1,vt) ① (esp. 開ける) to open (a door, etc.); to unwrap (e.g. parcel, package); ② (esp. 開ける) to open (for business, etc.); ③ (esp. 空ける) to empty; to clear out; to make space; to make room; (v1,vi) ④ (esp. 明ける) to dawn; to grow light; ⑤ (esp. 明ける) to end; (P)

OK, not quite the same senses for all (each sense is given a "preferred" kanji), but still seems to claim that there might be cases where one kanji spelling could be used instead of another.

Is this an error in JMDict (and should all three have separate definitions), or can anybody think of cases where the above spellings are used instead of one another?

Edit: to clarify, my question could be summed up as:

• Does your dictionary disagree with mine?

if not:

• Can you give me one situation example where any two of the above spellings could be used interchangeably (with or without minor differences in nuance)?

Answer

Historically, all of these are indeed the same word, which had a base meaning of "clearing an obstruction". From this base meaning you can easily get to "making/getting empty" and "opening".

As for the meaning of "brightening", if I understand correctly, the story goes like this: Since ancient time had a metaphor of dawn (夜明け) as the night (夜) clearing up (あける) the obstruction it has put on the sky, and allows the light to flow freely. From the same root (ak-) also come the words 明るい and 赤い. Yes, the color that is associated with the night clearing up is red and not white, because the reddish hue that often accompanies dawn (though we're more likely to associate reddish hue with sunset in our western imagery).

All of these words and senses seems to be of very old origin, i.e. they had formed well before kanji came to be used for writing Japanese. When the Japanese had to fit the Chinese kanji (which were obviously tailored around Chinese words and meanings) to their language they obviously couldn't find a single kanji that would convey all of the senses of あける together.

Most of the kanji associations that evolved into what we now know as kun-readings came from an old writing system called kanbun, that barely had any phonetic elements. Japanese written in kanbun was effectively translated to Chinese and even laid out in Chinese syntax (though later some reading aids were added to help readers convert it back to Japanese syntax), and at least in the beginning, it had to be acceptable Chinese, so the writer had to replace あける with 開 (remember, there was no okurigana in the first kanbun texts) when it meant 'open', with 空 when it meant 'empty' and with 明 when it meant 'brighten'. Over the time these distinctions stuck, and up till today most Japanese choose the appropriate kanji for each meaning. In my personal experience, these meanings have grown so distinct in modern language that you'd usually find people "confusing" the kanji only when their IME misfires (which happens quite a lot :)) or when they try to make a word-play.

Dictionaries are another thing though, and since most of them base their entry partition (at least partially) on etymological grounds, they may end up putting all of these kanji under one unified entry (often with usage guidelines, but still under one roof).