The word たわい is usually used in the form たわいない.
In classical language, たわい had the meaning of drunkenness.
Usually written in kana. The kanji form 他愛 is ateji and rare.
Ateji (phonetic) spelling; rarely used in modern writing.
The origin is uncertain. The kanji 他愛 is ateji (phonetic) and does not reflect the meaning. The word is now mostly fossilized in the negative form たわいない.