Ponderous

Ultimately from Latin ponderÅsus ("weighty").

Full definition of ponderous

1879, Julian Hawthorne, Archibald Malmaison, ch. 5:He saw, at the end of a shallow embrasure, a ponderous door of dark wood, braced with iron.
circa 1920 Edgar B. P. Darlington, The Circus Boys on the Flying Rings, ch. 4:The great elephant, when the cage was being placed, would, at a signal from its keeper, place its ponderous head against one side of the cage and push.

1781, Samuel Johnson, Lives of the Poets, "Dryden":It was Dryden's opinion . . . that the drama required an alternation of comick and tragick scenes; and that it is necessary to mitigate, by alleviations of merriment, the pressure of ponderous events, and the fatigue of toilsome passions.
1845, Charles Dickens, Pictures From Italy, ch. 11:In its court-yardâ€”worthy of the Castle of Otranto in its ponderous gloomâ€”is a massive staircase.
1915, Virginia Woolf, The Voyage Out, ch. 19:For the time, her own body was the source of all the life in the world, which tried to burst forth hereâ€”thereâ€”and was repressed now by Mr. Bax, now by Evelyn, now by the imposition of ponderous stupidity.

1915, Samuel Hopkins Adams, Little Miss Grouch, ch. 10:Slowly, through an increasing glow that lighted land and water alike, the leviathan of the deep made her ponderous progress to the hill-encircled harbor.
1919, Virginia Woolf, "Kew Gardens":Following his steps . . . came two elderly women of the lower middle class, one stout and ponderous, the other rosy cheeked and nimble.

1863, Elizabeth Gaskell, "Cousin Phillis":Over supper the minister did unbend a little into one or two ponderous jokes.
1918, Gene Stratton-Porter, A Daughter Of The Land, ch. 2:As certainly as any one said anything in her presence that she had occasion to repeat, she changed the wording to six-syllabled mouthfuls, delivered with ponderous circumlocution.

circa 1660 Thomas Manton, "Sermon Upon John III" in Works of Thomas Manton (2002 edition), ISBN 9781589603462, p. 464:Ponderous thoughts take hold of the heart; musing maketh the fire to burn, and steady sight hath the greatest influence upon us.
1804, The Literary Magazine and American Register, vol. 2, no. 7, p. 10:The acute and ponderous mind of Dr. Johnson was not always right in its decisions.
1850, Fraser's Magazine for Town and Country, vol. 41, p. 242:They are the pleasantest of all companions, and perhaps the most affluent in correct opinions of men and things generally, although little addicted to ponderous consideration or deep research.