[sebastiennight]

How is "development" an adverb or adjective turned into a noun??

It comes from a French word (développement) and that in turns was just a natural derivation of the verb "développer"... no adverbs or adjectives (English or otherwise) seem to come into play here

[capnrefsmmat]

Sorry, I should have said adjectives or verbs, as it's "develop" turned into a noun. Just like "discernment" or "punishment". The etymology isn't relevant for classifying it as a nominalization, only the grammatical function.