Antonyms for the word "more well-developed" include "less developed," "underdeveloped," "undeveloped," "primitive," and "backward." These are terms used to describe things that are not fully or adequately developed, such as economies, technologies, infrastructures, and individuals. For example, an underdeveloped country might lack access to basic necessities like clean water, education, and healthcare, whereas a developed country boasts high standards of living and advanced infrastructure. Similarly, an undeveloped technology or product might be outdated, unreliable, or ineffective. Antonyms provide a useful way to contrast or compare different aspects of our world, highlighting the disparities and potentials for growth and improvement.