What does the word contralto mean?

Contralto: A low female voice; the lowest adult female voice type, with a vocal range that typically spans from F3 to F5. Contraltos have voices which are darker and richer than those of mezzo-sopranos and sopranos. The contralto's tessitura can extend below and above these pitches for specific works or styles with more flexibility than most soprano and mezzo voice parts have above A5—or in the case of coloratura contraltos even above C6—and many contraltos sing lower than F3 as part of their usual repertoire