This package provides the file /usr/share/dict/american-english-huge containing a list of English words with American spellings. This list can be used by spelling checkers, and by programs such as look(1). . This is an even larger list than the one installed by wamerican-large; nothing prevents you installing both (and others) at the same time. . There are also -small and standard versions of this word list, and there are wbritish* and wcanadian* packages as well.
