deep blue sky; bottomless blue sky
A set phrase describing a vividly clear, deep blue sky that seems to go on forever. Often used in literary or poetic descriptions.
We enjoyed a picnic under the deep blue sky.
In autumn, there are many days when the bottomless blue sky spreads out.
Standard kanji-kana mixed spelling for this set phrase.
Kana spelling of the first part; sometimes used for emphasis or in informal writing.
The phrase combines 抜ける (to come out, to be transparent) with 青空 (blue sky), literally 'a blue sky like it's coming out', suggesting a sky so clear and deep it feels as if you could pass through it. The exact origin is uncertain, but it is a conventional poetic expression.