Fruitful is an adjective which describes a plant or tree which produces a lot of fruit or in people, those who produce many children or offspring. If you describe something as fruitful it means it produces good or appeasing results. 

1. Claire has been trying her best to find a new place to live, but so far her efforts have proved fruitless.
2. The wedding ritual includes an offering to guarantee a fruitful marriage.
3. Planting two trees close together improves the chances of a fruitful crop.
4. My efforts to save money this year so far have been fruitful.

1. I had a fruitful discussion with the potential investor this morning. I'm hopeful that she'll put some capital into the business.
2. The contract with our new supplier was only signed a month ago, but so far it has proved to be a very fruitful relationship.
3. Luke has made thousands from his share of the business. It really has been a fruitful investment for him.