Unfruitful (adjective)

Not producing good results or results that are expected; barren; not productive.

Origin:

From un- (not) + fruitful (producing good results or results that are expected).

Examples:

1. The land was unfruitful, so the farmer had to find a new place to grow crops.
2. The meeting was unfruitful, so the CEO decided to cancel the next one.
3. The conversation was unfruitful, so the friends decided to change the topic.
4. The research was unfruitful, so the scientists decided to start again.
5. The training was unfruitful, so the coach decided to change the method.