FYI (not because it’s particularly relevant to the sort of hashing that is being talked about, but because it’s a useful piece of info that might interest people, and corrects what I think is a misunderstanding in the parent comment): perfect hash functions are a thing, and are useful: https://en.wikipedia.org/wiki/Perfect_hash_function. So long as you’re dealing with a known, finite set of values, you can craft a useful perfect hash function. As an example of how this can be useful, there’s a set of crates in Rust that make it easy to generate efficient string lookup tables using the magic of perfect hash functions: https://github.com/sfackler/rust-phf#phf_macros. (A regular hash map for such a thing would be substantially less efficient.)

Crafting a perfect hash function with keys being the set of words from the OED is perfectly reasonable. It’ll take a short while to produce it, but it’ll work just fine. (rust-phf says that it “can generate a 100,000 entry map in roughly .4 seconds when compiling with optimizations”, and the OED word count is in the hundreds of thousands.)