heavy, lumbering, ponderous -- (slow and laborious because of weight; "the heavy tread of tired troops"; "moved with a lumbering sag-bellied trot"; "ponderous prehistoric beasts"; "a ponderous yawn")
ponderous -- (having great mass and weight and unwieldiness; "a ponderous stone"; "a ponderous burden"; "ponderous weapons")
ponderous -- (labored and dull; "a ponderous speech")
(Sound)
