The word "加倍" is formed by combining two individual characters, each with its own core meaning, to create a new, unified concept. The first character, 加 (jiā), fundamentally means "to add" or "to increase". The second character, 倍 (bèi), carries the meaning of "double", "times", or "multiple". When joined, the concept of "adding" merges with the concept of a "multiple", directly producing the combined sense of "to double" or "to redouble", literally meaning to increase by a fold or multiple of the original.