The word 不断 is formed through the conceptual combination of its two constituent characters: 不 (bù), meaning "not", and 断 (duàn), meaning "to cut off" or "to break". By literally joining "not" with "break", the compound visually and logically creates the abstract idea of an unbroken sequence, where something is not severed or interrupted. This formation relies on a metaphorical extension from the physical act of breaking to the abstract state of continuity, resulting in the meaning of "unceasing" or "continuously".