This is the 19567th most frequent Korean word.
어두운
"어두운" means "dark."
In this sentence, "어두운" is used as an adjective describing the dim or unlit physical conditions of the night road.
어두운 밤길을 혼자 걷는 것은 위험할 수 있습니다.
Walking alone on a dark night road can be dangerous.
Here, "어두운" metaphorically represents a mood or tone that is grim, somber, or serious.
그 영화는 분위기가 매우 어두웠다.
That movie had a very dark atmosphere.
In this context, "어두운" figuratively describes a situation or future prospect that lacks optimism or positivity.