The adjective ponderous means a writing or speech that is very serious and dull, or something that is slow and awkward because of being very heavy or large.
Synonyms are bulky, massive, huge, or burdensome.
The word origins from Latin (1400) ponderosus meaning “of great weight, full of meaning”, from pondus (genitive ponderis) meaning “weight” and stem of pendere meaning “to hang”. Its meaning “tedious” is first recorded in 1704.
The audience was bored by his ponderous speech.
The sound of his ponderous steps scared the little children.
He avoids being burdened by that ponderous work.