倍

Fold or multiple; refers to both specific doubling (2x) and general multiplication of scale or number.

Used as a numeral/classifier to define the scale of an increase (e.g., 三倍), as a verb meaning to double, multiply, or augment, or as a qualitative modifier indicating intensification or something "out of proportion" (excessive).

Contrast with:

• 重 (chóng): refers to layering or stratification (additive/physical folds) rather than multiplicative total.
• 複 (fù): emphasizes the act of duplication or the state of being double.
• 乘 (chéng): in later texts, this becomes the technical term for mathematical multiplication; 倍 often performs this function in earlier texts.

Be alert to the "$n$ vs $n+1$" problem: determine if the text implies a final total amount ($n$) or an additional increase added to the base ($n+1$). Use surrounding numerical data to resolve the ambiguity.