I'm an amateur coder building a completed computer version of the game Countdown. I'd like the game to validate players' word answers and ideally provide each accepted word's spelling, syllable count, and definition. I first considered downloading the entire Oxford English Dictionary to a Chromebook, or possibly an iMac, but I'm unsure whether that's technically feasible or legally permitted. Would a downloadable word database, dictionary API, or another resource be more suitable?
4 Answers
The computer should have no trouble handling a word list of this size; storage and processing aren’t the main obstacles. The important issues are licensing and choosing data that matches the game’s rules. Syllable counting can be estimated with a rules-based script, but English has enough exceptions that you’ll want to review or correct the results for the words included in your game.
For a prototype, a public dictionary API could be easier than downloading a large database. You can look up definitions when needed, though an offline word list is usually better for gameplay because it avoids network delays and service limits. Syllable counts can be precomputed and stored alongside the words.
You probably don’t need a complete general-purpose dictionary. Countdown-style validation mainly requires the game’s accepted word list, ideally matching the specific dictionary used by the show. Community-created lists may contain just the playable words, which keeps the data smaller and avoids storing material you don’t need. Definitions could be added separately from a licensed or free dictionary source.
The Oxford English Dictionary is copyrighted, so downloading and redistributing its content for a game isn’t an appropriate route. A better starting point is a free resource such as Wiktionary or Princeton’s WordNet, both of which can provide downloadable lexical data under their respective terms. Check the license carefully before including anything in a released game.

That makes sense. I was initially thinking about definitions too, but a reliable word list may be enough for validating answers while I work out the rest.