"Ah-mawnt sohmbr" or "Ah-mawnt sohm-bruh" are pronunciations of the French phrase amante sombre.
Specifically, the first pronunciation can be found more in the center and north of France. The second pronunciation can be found more in southern France. But either way, the feminine noun amante means "(female) lover." The feminine/masculine adjective sombre means "somber."
sombre
Sombre
dark is sombre or foncé(e) in French.
Eau Sombre
Le sombre
Mince (et) sombre is a French equivalent of the English word "slim-shady." The pronunciation of the feminine/masculine singular phrase -- which appears most famously as the alter ego of Missouri-born rapper Eminem (born Marshall Bruce Mathers III, October 17, 1972) -- will be "mehs somb" in northerly French and "mehs (sey) som-bruh" in southerly French.
"il fait sombre" means "it's dark" when translated from French to English
Une nuit sombre
Noir (color or ambiance) Sombre (ambiance)
Quelle journée lugubre/sombre/morne
The word "shady" in French can be translated as "sombre" or "douteux."
Dark angel: Ange sombre