These are the winning words from every National Spelling Bee since 1925

Peg McCarthy of Topeka, Kansas, spells the world “deification” to win the 51st National Spelling Bee in Washington, D.C., June 8, 1978. The runner-up Lyn Sue Kahng, seated left, puts her head in her handsAP

The 90th Scripps National Spelling Bee kicked off on Wednesday with nearly 300 young spellers from around the country gunning for a $40,000 top prize.

The field of 291 children will be whittled down to one champion at Thursday’s final in Oxon Hill, Maryland.

Since the inaugural competition in 1925, the words featured in the bee have become increasingly more difficult and obscure, requiring participants to have a commanding knowledge of root words, etymology, and world languages.

Scripps’s list of “winning words” from previous competitions gives a glimpse at this evolution. Relatively simple words such as “knack,” “therapy,” and “initials” dominated earlier installments of the spelling bee, while modern-day champions have had to tackle humdingers like “feuilleton,” “nunatak,” and “gesellschaft.”

The shift in difficulty can be partly attributed to ESPN’s coverage of the bee, which has attracted more students to the competition, Scripps spokeswoman Valerie Miller said. This is the 24th year ESPN will air the spelling bee.

But the biggest reason is simply that the spellers have gotten better.

“Words are more difficult now because the skills of the students also have expanded,” Miller told Business Insider. “These are the best of the best spellers, and the words they get in the national finals should be the greatest challenge.”

Here are some of the championship-clinching words from previous spelling bees: