Jacyf & mEnglish Popular in Westerns and Western romances for both male and female, white and Native American characters. It is probably a variant of Jessie 1 or Jesse, a name popular in the American West for both men and women.
JadeyfEnglish (Rare) Diminutive of Jade, or a feminine variant of Jaydee. A known bearer of this name is the English actress and film producer Jadey Duffield (1991-).
JamiroquaimEnglish (Modern, Rare) In the case of the band of the same name, which influenced first name usage in the 1990s and 2000s, they conceived it as a combination of jam and iroquai (the latter of the two is based on the Native American confederacy, the Iroquois).
JancisfEnglish (Rare) Blend of Jan 2 and Francis. This name is most notably borne by Jancis Robinson (b. 1950), an English wine critic, journalist and author who has won multiple awards for her work.