Fecund is a formal word that typically describes a person, animal, or plant that is producing or able to produce many offspring. It is synonymous with fertile and fruitful. Fecund is also used figuratively to describe something especially intellectually productive or inventive, as in “a fecund source of ideas.”
The farm’s fecund fields abounded with produce.
The Franklin stove, bifocals, and the lightning rod are just a few of the inventions that we owe to the fecund creativity of Benjamin Franklin.