To change with a specific direction, progress.

“Let's see how things develop and then make our decision.”

To progress through a sequence of stages.

“Isabel developed from a tropical depression to a tropical storm to a hurricane.   An embryo develops into a fetus and then into an infant.”

To advance; to further; to promote the growth of.

A process of development.

In the process of development.

“a developing foetus”

Of a country: becoming economically more mature or advanced; becoming industrialized.