noun
betraying one's love; going against love
A noun phrase describing the act of betraying love or acting contrary to love. Often used in poetic or dramatic contexts.
彼の行動は愛に背くものだった。
His actions were a betrayal of love.
愛に背くことは、自分自身を傷つけることだ。
To betray love is to hurt oneself.
背く is a verb meaning 'to betray' or 'to go against'. 愛に背く is a specific noun phrase using that verb.
Compound of 愛 (love) + に (particle) + 背く (to betray). The exact historical derivation is uncertain, but it follows a common pattern of verb phrases nominalized.