cool words no one uses anymore

cosmogyral (adj) 1808 -1808
whirling round the universe
“The great cosmogyral peregrinations of galaxies follow simple physical laws.”

ephydriad (n) 1823 -1823
“The synchronized swimmers were like ephydriads, full of natural grace.”

essomenic (adj) 1771 -1771
showing things as they will be in the future
“The essomenic properties of crystal balls are very much in dispute.”

eternitarian (n) 1746 -1746
one who believes in the eternity of the soul
“Though she held to no particular faith, she remained a hopeful eternitarian.”

hirquitalliency (n) 1652 -1652
strength of voice
“The wrestler’s hirquitalliency compensated for his lack of strength and talent.”

isangelous (adj) 1768 -1774
equal to the angels
“I’ve had just about enough of her isangelous and self-righteous diatribes.”

medioxumate (adj) 1723 -1723
of gods of intermediate rank between those of heaven and of hell
Medioxumate deities such as those of the Greek pantheon are rarely worshipped today.”

nequient (adj) 1656 -1656
not being able
“While the other students understand algebra, you are still nequient in this simple art.”

sevidical (adj) 1656 -1656
speaking cruel and harsh words; threatening
“I will not tolerate your sevidical tone and manner!”

solennial (adj) 1623 -1656
occurring once a year; annual
“Welcome to our solennial celebration of the birth of our illustrious institution.”

sparsile (adj) 1891 -1891
of a star, not included in any constellation
“The prevalence of sparsile stars today reflects technical advances in telescopy.”

thural (adj) 1624 -1714
of or pertaining to incense
“The mysteries of the ancient order involved the burning of thural herbs.”

vacivity (n) 1656 -1721
“The vacivity of her mind can hardly be a consequence of her blonde hair.”

from here