While looking at a novel physical entity, two-year-old Koreans heard the entity named. They were then asked to extend the name to new entity that preserved either shape or material of the original entity. When the entities were solid objects, children extended the words on the basis of shape, but this shape preference was graded depending on shape complexity of the objects. Interestingly, however, even when the entities were made from non-solid substances, the tendency to respect shape was also graded depending on the shape complexity of the entities, suggesting that ontological distinction between solid objects and non-rigid substances and perceptual complexity interact in interpreting nouns for novel entities.