The word "那时" is formed through the direct and logical combination of two fundamental conceptual characters: "那" (nà), which functions as a pointing word to indicate something distal, similar to "that", and "时" (shí), which represents the abstract concept of "time" or "a moment". Their fusion creates a new, fixed unit where the spatial sense of pointing ("that") is applied to the dimension of time, resulting in the meaning "that time" or "at that moment". It is a conceptual compound where the whole meaning emerges from the straightforward modification of one character's core idea by the other.