Yōga Sūtra 1.08

विपर्ययो मिथ्याज्ञानमतद्रूपप्रतिष्ठम्।

Viparyaya, i.e. misunderstanding or overthinking, is the incorrect knowledge inferred by seeing the form, which is not.

In a dull light, if you see a rope and conclude it as a snake, it is a misunderstanding. During eclipse, if you assume the sun is harmed, it is overthinking.