Dutch word avondval comes from Dutch des avonds, Dutch val

Detailed word origin of avondval

Dictionary entry	Language	Definition
des avonds	Dutch (nld)
val	Dutch (nld)	(obsolete) catfish (in compounds) case. (in compounds) nightfall. Downfall, demise. Fall (act of falling). Trap, snare.
avondval	Dutch (nld)	Nightfall, sundown.