1.
Something that is ~ produces good and useful results.
We had a long, happy, ~ relationship...
The talks had been ~, but much remained to be done.
= productive
ADJ
~ly
...taking their skills where they can be applied most ~ly.
ADV: ADV with v
2.
Fruitful land or trees produce a lot of crops.
...a landscape that was ~ and lush.
= fertile
ADJ