Easton's Bible Dictionary (1897)
(Heb. tsab, as being lightly and gently borne), a sedan or palanquin for the conveyance of persons of rank (Isa. 66:20). In Num. 7:3, the words “covered wagons” are more literally “carts of the litter kind.” There they denote large and commodious vehicles drawn by oxen, and fitted for transporting the furniture of the temple.
Hastings' Dictionary of the Bible (1898) & Schaff's Bible Dictionary
LIT'TER, a covered chair sheltering the occupant against rain and the sun, and carried either by men or animals. Isa 66:20.