This is the 14806th most frequent Russian word.
плохое
"Плохое" means "bad" or "poor" in English.
Here "плохое" operates as a neuter singular noun, derived from the adjective, signifying 'bad things' or 'bad situations in general.'
Иногда плохое становится полезным уроком.
Sometimes the bad becomes a useful lesson.
Here, "плохое" is used as an attributive adjective describing "событие," highlighting its negative or undesirable nature.
Каждое плохое событие оставляет след в жизни.
Every bad event leaves a trace in life.
In this case, "плохое" functions as a neuter singular adjective used substantively with "что-то," indicating something of negative or undesirable quality.