spell—finds spelling errors

spell [ –blvx ] [ –d hlist ] [ –s hstop ] [ +local_file ] [ filename]...

spell collects words from the named filenames and looks them up in a spelling list. Words that neither occur among nor are derivable from (by applying certain inflections, prefixes, and/or suffixes) words in the spelling list are printed on the standard output. If no filenames are named, words are collected from the standard input.