'Chǔn de' is a grammatical structure, not a standalone word. It consists of the adjective 蠢 (chǔn, 'foolish') followed by the particle 得 (de), which introduces a complement describing the degree or result of the adjective — similar to 'so...that...' in English. This pattern expresses an extreme or exaggerated level of foolishness, often with irony, frustration, or humorous exaggeration.

The structure always follows the pattern 'Adjective + 得 + Complement', where the complement explains how foolish, to what extent, or what consequence results from the foolishness. It’s commonly used in informal speech and writing, especially when criticizing someone’s poor judgment or absurd behavior. Unlike standalone adjectives, 'chǔn de' cannot appear without a following complement — saying just '他蠢得' is incomplete and ungrammatical.