'slowly-developed' originates from the combination of 'slowly,' an adverb meaning 'at a slow pace,' and 'developed,' the past participle of 'develop,' which comes from the Old French 'desveloper,' meaning 'to unwrap or unfold.'

'developed' changed from the Old French word 'desveloper' and eventually became the modern English word 'developed.'

Initially, 'developed' meant 'to unwrap or unfold,' but over time it evolved into its current meaning of 'to grow or cause to grow and become more mature, advanced, or elaborate.'