Final answer:
The word that replaces 'understandability' when a country's colony becomes more developed is 'Development', related to the process of modernization and economic growth.
Step-by-step explanation:
When a country's colony becomes more developed, the word that replaces "understandability" in this context is Development. Modernization describes the processes that increase the amount of specialization and differentiation of structure in societies, resulting in the move from an undeveloped society to a developed, technologically driven society. Economic Development is integral to the transformation of a society and leads to qualitative changes in virtually every aspect of life within a country.