Unless you know you need the FreeBSD word pool (or are curious), use the standard pool. It's especially well-suited to identifying English spelling patterns.
If the default search fails, then you can try the FreeBSD word pool, which is a much larger word pool. Note that it also includes proper nouns, which (like loan words) will often break ordinary English spelling patterns.
Click on the Search Pattern Help button for general advice on using the Word Searcher.
By default, the Word Searcher references an edited copy of the British English inflected word set from the '12dicts' lists compiled by Alan Beale and available at 12dicts-4.0.zip.
There are around 60000 words in the list, including inflected versions, but no abbreviations, hyphenations, names or phrases. The author warns that some Americanisms may have crept in. Given the international use of the tool, that may be less of a problem than I at first feared.
The emphasis is on common words, rather than archaic, scientific or jargon words.
The FreeBSD pool is a partial copy of a much wider (but also much wilder) list produced by The FreeBSD Project. It includes proper nouns, and there may be some unattested words.
Because the FreeBSD pool is so large, searches of it are limited to the first 1000 words found.
Copyright Neil Ramsden 2004-2012.