Noun
bittersweetness (uncountable)
The state or condition of being bittersweet.
The bittersweetness of uncertainty: To win or to lose. Markus Zusak
It’s a line that reflects the bittersweetness at the film’s heart: at the heart of patriarchy is the notion that women exist for men’s purposes, whether for sex, property, or adoration. Source: Internet
Your music is so joyful and high-energy (with a bit of bittersweetness in the lyrics). Source: Internet