This is the 13819th most frequent Russian word.
нужное
"Нужное" means "necessary" or "needed."
The word 'нужное' is used as a nominalized adjective meaning 'necessary things' or 'essentials'.
Я взял всё нужное для поездки.
I took everything necessary for the trip.
Here, 'нужное' is used as a nominalized adjective meaning 'appropriate' or 'fitting solution'.
Нужное решение оказалось проще, чем мы думали.
The right solution turned out to be simpler than we thought.
In this sentence, 'нужное' refers to 'what is needed or suitable' in a given situation.