To clarify these points, I would ask you to read this passage from the revised version of "The Beast of Averoigne," by Clark Ashton Smith, published in 1933.
"As all men know, the advent of the Beast was coeval with the coming of that red comet which rose behind the Dragon in the early summer of 1369. Like Satan's rutilant hair, trailing on the wind of Gehenna as he hastens worldward, the comet streamed nightly above Averoigne, bringing the fear of bale and pestilence in its train. And soon the rumor of a strange evil, a foulness unheard of in any legend, passed among the people.
"To Brother Gerome of the Benedictine Abbey of Perigon it was given to behold this evil ere the horror thereof became manifest to others. Returning late to the monastery from an errand in Ste. Zenobie, Gerome was overtaken by darkness. No moon arose to lantern his way through the forest; but, between the gnarled boughs of antic oaks, he saw the vengefully streaming fire of the comet, which seemed to pursue him as he went. And Gerome felt an eery fear of the pit-deep shadows, and he made haste toward the abbey postern.
"Passing among the ancient trees that towered thickly behind Perigon, he thought that he discerned a light from the windows, and was much cheered thereby. But, going on, he saw that the light was near at hand, beneath a lowering bough. It moved as with the flitting of a fen-fire, and was of changeable color, being pale as a corposant, or ruddy as new-spilled blood, or green as the poisonous distillation that surrounds the moon.
"Then, with terror ineffable, Gerome beheld the thing to which the light clung like a hellish nimbus, moving as it moved, and revealing dimly the black abomination of head and limbs that were not those of any creature wrought by God. The horror stood erect, rising to more than the height of a tall man; and it swayed like a great serpent, and its members undulated, bending like heated wax. The flat black head was thrust forward on a snakish neck. The eyes, small and lidless, glowing like coals from a wizard's brazier, were set low and near together in a noseless face above the serrate gleaming of such teeth as might belong to a giant bat.
"This much, and no more, Gerome saw, ere the thing went past him with its nimbus flaring from venomous green to a wrathful red. Of its actual shape, and the number of its limbs, he could form no just notion. Running and slithering rapidly, it disappeared among the antique oaks, and he saw the hellish light no more."
Smith often wrote of places far away in time, in stories that called for a style beyond the everyday language of our experience. Here we have medieval France, and adjectives that might seem unusual to modern readers, but notice, too, the strength of the verbs, the visual and physical details of the setting, the varied structure and length of the sentences. As archaic as many of the terms might seem, the other words compensate by making the place and the actions vivid.
Now consider this passage from Avram Davidson's The Phoenix and the Mirror (1969):
"Cyprus was another world.
"The city of Paphos might have been designed and built by a Grecian architect dreamy with the drugs called talaquin or mandragora: in marble yellow as unmixed cream, marble pink as sweetmeats, marble the green of pistuquim nuts, veined marble and grained marble, honey-colored and rose-red, the buildings climbed along the hills and frothed among the hollows. Tier after tier of overtall pillars, capitals of a profusion of carvings to make Corinthian seem ascetic, pediments lush with bas-reliefs, four-fold arches at every corner and crossing, statues so huge that they loomed over the housetops, statues so small that whole troops of them flocked and frolicked under every building's eaves, groves and gardens everywhere, fountains playing, water spouting....
Once again, we have terms that might seem unfamiliar to modern readers, but we also have a disciplined use of alliteration (dreamy with the drugs), parallel clauses (marble yellow, marble pink, marble green), assonance (veined marble and grained marble) and contrasting visible details to make the description vivid (statues that loom, statues that flock and frolic). The passage is both exuberant and controlled; it says what it needs to say, then stops.
Finally, a paragraph by Murray Gilchrist, from "Dame Inowslad" (1894).
"The would-be musician turned and showed me a long painful face with glistening eyes and a brow ridged upward like a ruined stair. It was a face of intense eagerness: the eagerness of a man experimenting and praying for a result whereon his life depends. Without any prelude he played a dance of ghosts in an old ball-room: ghosts of men and women that moved in lavoltas and sarabands; ghosts that laughed at Susanna in the tapestry; ghosts that loved and hated. When the last chord had sent them crowding to their graves he turned and listened for a footstep. None came. He lifted a leather case from the side of the stool and, unfastening its clasps, took out a necklace which glistened in the candlelight like a fairy shower of rain and snow. 'Twas of table diamonds and margarites, the gems as big as filberts. He spread it across the wires, and after an instant’s reflection began to play. The carcanet rattled and jangled as he went: it was as an advancing host of cymbal-women. When he listened again, great tears oozed from his eyes. He took up the jewel and played a melody vapid at first, but so subtle in its repetitions that none might doubt its meaning: thus and not otherwise would sound a lyke-wake sung in a worn voice after a night of singing. And whilst he played, the door opened silently, and I saw Dinah, there in her nightgown, holding the posts with her hands. She took one swift glance, then disappeared again in the darkness, and came back carrying in her arms a bundle swathed in pure linen and strongly redolent of aromatic herbs. Holding this to her breast, she approached the man. Her shadow fell across the keys, and he lifted his head. From both came a long murmur: his of love and joy and protection, hers of agony. He rose and would have clasped her, but she drew back and placed her burden in his outstretched hands."
Notice here, as in the previous passages, qualities hard to define but easy to feel: energy and flow. For all of their adjectives, for all of their elaborate syntax, these passages move with an economy and clarity that, for me, transcends any sense of old-fashioned style. Nothing creaks, here; nothing reeks of dust. What I find, instead, is a liveliness that keeps me alert and happy.