/dɪˈvɛləpmənt/
1.n.act of improving by expanding or enlarging or refining
“he congratulated them on their development of a plan to meet the emergency”
2.n.a process in which something passes by degrees to a different stage (especially a more advanced or mature stage)
“the development of his ideas took many years”
3.n.(biology) the process of an individual organism growing organically; a purely biological unfolding of events involved in an organism changing gradually from a simple to a more complex level
“he proposed an indicator of osseous development in children”