Ponderous (adj): Slow and clumsy because of high weight. (बोझल, भारी-भरकम, कष्टकारक)

Synonyms: Clumsy, Slow, Lumbering, Burdensome

Antonyms: Light, Airy, Ethereal, Feathery, Fluffy

Example: These ponderous pachyderms  are more commonly shown as elephants.

Uses:

A delay in positioning certain formations not only revealed the ponderous nature of India’s mobilisation plans, but also permitted Pakistan to counter-mobilise ahead of us.