This is the 11598th most frequent Swedish word.
onödan
"Onödan" means "the unnecessary" or "in vain" in English.
In this sentence, 'onödan' refers to doing something unnecessary or without need.
Du borde inte göra det där av ren onödan.
You shouldn't do that unnecessarily.
Here, 'in onödan' indicates that the effort expended was needless since the outcome didn't require it.
Det blev mycket arbete helt i onödan.
It turned out to be a lot of work completely unnecessarily.
In this context, 'onödigt' relates to spending resources in a manner considered wasteful or not required.