long night; long autumn night
Refers to the lengthening nights, especially in autumn. Often used in poetic or literary contexts. Compare with 日永 (ひなが, long day in spring).
See also: 日永
I enjoy reading on long autumn nights.
夜長の季節になると、つい夜更かししてしまう。
When the season of long nights arrives, I end up staying up late.
Standard kanji spelling.
Rare variant kanji spelling; 永 suggests 'long' or 'eternal'.
Compound of 夜 (yo, 'night') and 長 (naga, 'long'). The reading よなが is a standard kun'yomi combination.