bête noire

A person or thing that one particularly dislikes or fears.

• (no common derivatives)

• one's bête noire
• the bête noire of
• a particular bête noire
• long-standing bête noire

1. 1.Spreadsheets are my bête noire — I'd rather do anything than spend hours formatting data. (most hated thing)
2. 2.Traffic congestion has been the bête noire of urban planners for decades. (persistent problem)

• bugbear/ˈbʌɡbeə/— source of annoyance or fear
• nemesis/ˈnɛmɪsɪs/— formidable enemy
• pet peeve /ˈpɛt piːv/ (particular annoyance, informal)

French for "black beast" — bête (beast) + noire (black) — the dark creature one fears most