The word "弯弯曲曲" is formed through the reduplication of the two-character adjective "弯曲" (meaning curved or winding). Each character from "弯曲" is repeated in sequence, resulting in the AABB pattern where "弯" is doubled to "弯弯" and "曲" is doubled to "曲曲", combining to create an intensified descriptive form that emphasizes a high degree of curvature or twistiness.