In July 1915, the local paper in Le Mars, Iowa (which I note claims the title of ice cream capital of the world) reported on the curious events in Remsen, a small community ten miles to the east that even today has a mere 1,600 inhabitants. A man posing as a film-maker from Chicago had persuaded local businessmen to put up money to make a movie promoting the virtues of the town. His speech on the wonders of his camera, as reported, was impressively extravagant, though it ought to have reminded his hearers of the loquacity of a snake-oil salesman:
This instrument’s greatest achievement will be when it portrays to the world the gorgeous glory, the scintillating splendor, the cyclopean characteristics which will not a little magnoperate the massiveness of your wonderful community.
Le Mars Semi-Weekly Sentinel, 20 Jul. 1915.
Had the unidentified man really said magnoperate, or had he been grandiloquised by the newspaper? Either way, I suspect a prior consultation of the M-Mandragon section of the Oxford English Dictionary, which had been published in 1904. That recorded only two occurrences of the word, its first being in 1610, in a dedication in Baculum Geodæticum, an important work on surveying by the almanac maker and mathematician Arthur Hopton. It was in a dedication, an even more grovellingly flattering speech than that of the conning cameraman, but its relevant part may remind you of his spiel: “[It] will not a little magnoperate the splendor of your well knowne honour to these succeeding times”.
Magnoperate here means to enhance or make greater. It has nothing to do with either magnets or magic but comes from classical Latin magnopere. That’s short for magno opere, which literally means “with great labour”, but magnopere was applied figuratively to mean “to a great extent”, “greatly” or “especially”. We still know the Latin root of opere as opus, an artistic work; a close relative is opera, which came into English via Italian. Both elements of magnopere appear in magnum opus, great work, the most important creation of an artist or writer. It’s also, of course, the source of operate and its compounds (and opulent, since for Romans the root of wealth was work).
The word, with compounds magnoperation and magnoperator, popped up a few more times in the twentieth century. It was a favourite of the British theatre critic James Agate, who used it to mean doing something in the grand manner (“I like women to write femininely and cattily. They embarrass me when they magnoperate and magniloquise.”)
Nobody since him has employed it, not even the most magniloquent of silver-tongued persuaders.