I'm an amateur coder building a finished computer version of the game Countdown. I'd like the program to validate players' answers and ideally provide each word's spelling, syllable count, and definition. I initially considered downloading the entire Oxford English Dictionary, but I'm unsure whether that's possible or appropriate on a Chromebook or iMac. Would a freely downloadable dictionary or a game-specific word list be a better option?
3 Answers
The Oxford English Dictionary is copyrighted and isn’t generally available as a freely downloadable database for use in your game. A better starting point would be a free resource such as WordNet or Wiktionary, while checking the relevant license before distributing your game. You may need to combine the word list with a separate source for definitions and syllable counts.
You probably don’t need the whole dictionary. Countdown uses a particular accepted-word list, so finding a list based on the game’s dictionary would make answer checking much simpler. It may only contain the words, but you can calculate syllables with a heuristic or add a separate pronunciation dataset. No syllable-counting method will be perfect, so consider treating it as a best-effort feature.
A public dictionary API or downloadable lexical database could save you from storing and maintaining a huge amount of data. Look for one that explicitly permits redistribution and commercial or noncommercial use. Also, only words of the required lengths need to be loaded for each round, so the program can keep its memory use very small.

That makes sense—I was mainly thinking about definitions, but a game-specific list would be much more practical for validating answers.