Jennifer is the Cornish form of Guinevere, the Welsh Gwenhwyfar, and means "white phantom" or "fair one". It was a rarity outside Cornwall until the 20th century, then became the most popular girls' name in the United States every year from 1970 to 1984, the name of a whole generation. Jennifer still ranked number 26 in 2000, but has fallen steadily since and stands at number 586 in 2025.