vetkuri

Decode it: bet plus run. Veti is to bet at rank 1,244 and kuri is to run at 393, and vetkuri is the two of them welded together. That is the whole word. English needs a separate Latin borrowing, race, for the same idea; Esperanto reaches for two roots a beginner already owns and stops. If you can say the halves you can say the word, and better than that, you can hear what the word is claiming: a race is a run with a wager on it.

The nouns come free. Vetkuro is a race, the single event you turn up to watch. Vetkurado is racing, the ongoing activity, because -ad- is the suffix for a process rather than an instance. A vetkuristo is a racer and a vetkurejo is the racecourse. None of that has to be taught separately, which is the point of a compounding language: one root pair, a whole field of vocabulary.

Not the same as competing. Konkuri is to compete in general, over anything at all, and a konkurso is an organised competition with entrants and a prize. Vetkuri is narrower and more physical: legs, horses, cars, boats against each other over a distance. Use konkuri for two shops in the same street, vetkuri for two ĉevaloj on the same field.