Definition of soundex:
(n) :
(information science) A phonetic algorithm for indexing names by their English pronunciation, based on the most probably significant consonants, so that a search for a misspelled name may find the desired one.
(v) :
(information science, transitive) To index using the phonetic Soundex algorithm.
(n) :
Alternative letter-case form of Soundex. [(information science) A phonetic algorithm for indexing names by their English pronunciation, based on the most probably significant consonants, so that a search for a misspelled name may find the desired one.]