excelsior
Loftier, yet higher, more elevated; ever upward.
archaic, rare
There was with him a whole host of moral heroes, who, conscious of their power to win the victory , and quickened by the inspirations which they received from that higher state of being, were striving, by the excelsior movement of the soul, to attain to those glory-encircled heights from whence they could look calmly down upon the plane of their earthly existence.
More surpassing, more excelling.
archaic, rare
It was clear from the first three paragraphs that the language employed by Mr Tolkien was excelsior. He was brilliant.
Where it comes from
From Latin excelsior, comparative of excelsus (“high”). The name of the stuffing material was originally a trademark. As an exclamation, originating in Henry Wadsworth Longfellow's poem Excelsior (1841), based on the New York state motto. Popularized in the comic book fandom by Marvel Comics editor Stan Lee, who chose the term to sign off his columns as it was an obscure term and would confound competing publishers who imitated his style.
Adapted from the Wiktionary entry excelsior (CC BY-SA 4.0).