Look a word up or check its spelling from a command line in the page. Four sources are built in: Webster's Revised Unabridged Dictionary of 1913, WordNet, Wiktionary and Wikipedia. Fuzzy matching catches misspellings, so a word you cannot spell is still a word you can find.
The interactive picker narrows the word list as you type, the same way the installed binary does, and answers with the same definitions. It is the whole tool compiled to WebAssembly and run in a terminal in the tab.
Source code: github.com/0magnet/dict. More Go and WebAssembly projects: magnetosphere.net/software.