The word 抱怨 is formed by combining two characters that together create a vivid conceptual image. The first character, 抱 (bào), means "to embrace" or "to hold", and the second, 怨 (yuàn), means "resentment" or "grievance". Thus, the compound visually and conceptually depicts the act of holding onto resentment, as if clasping discontent to oneself, which naturally extends to the meaning of expressing that pent-up feeling, hence "to complain".