A name dictionary alphabetically lists first names, accompanied by their pronunciation, origin or ethnicity, meaning or interpretation, namesakes, alternate spellings, popularity, the usual gender of their owner, and related names. They are usually consulted by new parents wanting ideas for names for their baby or by those curious about the meaning and origin of their own name. Some name dictionaries might focus on a certain language of origin, promise unusual and creative names, or be especially well researched for an academic audience.
A name dictionary specific to a certain need could cover Christian and Biblical names, androgynous names, names with a cultural origin such as Celtic, or just have sections devoted to these categories. These help parents who want to choose a name that will work no matter if they have a boy or a girl, or parents who want to preserve the cultural heritage of their family. They don't have to sift through names that don't appeal to them. They'd learn about common male names like John, David, and Richard, and uncommon ones like Cornelius, Arlington, and Bow.
Online name dictionaries have multiple, more sophisticated research options. You can even reverse-search, deciding upon a meaning you want your child to embody, and find a name to match it. For "King" you would find the Persian name Xerxes and English name Maximillian. Names related to water would yield the Native American Nebraska, meaning "flat water," and Hebrew name Delilah, meaning, "to draw water." Sometimes these names are actually words in other languages that have been translated, but often the name has come to be associated with a certain symbol. Even more specific, parents can search for a name with a certain number of syllables, beginning letter, matching first and middle names, or level of popularity.
For example, let's look at an entry for the common name Elizabeth: Gender: Female. Pronunciation: Eh-liz'-ah-beth or Ah-liz'-ah-beth. Alternative spelling: Elisabeth. Etymology: English form of the Greek, Elisabet, derived from the Hebrew, Elisheba. In the Hebrew Bible, Elisabeth means "God's oath" or "devotion." Shorter versions, nicknames, and abbreviations: Elisa, Elise, Eliza, Beth, Betsy, Belle, Liz, Liza. Alternatives from other countries: Elisabetta (Italy), Elisabete (Portugal), Elizabeta (Slovenia). Famous namesakes: Queen Elizabeth of Britain, Elizabeth Taylor, Elizabeth Barrett Browning.