The word "漫长" is formed through a vivid conceptual combination where the first character "漫", which carries a sense of being unbounded, overflowing, or sprawling without limit (like water spreading), merges with the second character "长", meaning simply "long". This fusion does not just add length to length, but instead uses "漫" to imbue "长" with a qualitative, almost immersive feeling of vast, drawn-out, and immeasurable duration or extent, creating a sense of a longness that feels expansive, endless, and monotonous.