Avyapti under definition fallacy – UGC NET Question

Avyapti occurs when a definition does not extend to all objects that properly fall under the concept being defined. In such cases, some genuine instances are wrongly excluded, revealing that the defining characteristics are insufficient. This defect undermines the adequacy of the lakshana because it fails to capture the full extension of the term. Thus the under-definition mentioned in the stem is called avyapti.

Option A:
Option A, asambhava, refers to a definition that is impossible or self-contradictory, not merely too narrow. It signals a more radical failure than missing some instances.

Option B:
Option B, trairupya, names the marks of a valid hetu and belongs to the theory of inference, not to the analysis of definitions.

Option C:
Option C, ativyapti, is the opposite defect in which the definition is too broad, including things that should not be counted as instances.

Option D:
Option D is correct because avyapti literally means "non-pervasion" and pinpoints the failure of the definitional predicate to pervade the entire class that it is meant to characterise.