Jacobite: originally a term indicating a supporter of King James II (6 Feb (1685-11 Dec 1688), later sometimes used to indicate Catholic religion. See Maryland Protestant Revolution of 1689 and Secretaries of State: State Papers, Foreign, France (James COUMBES of Teignmouth, Devonshire and Paris France)

Jack: nickname for Jackson or John

Jacobus: (latin) given name, James (See also abbrev. Jas.)

Jain, Jane, Janet: nicknames for Jane, Joan, Jean, Janet (interchangeable during some eras)

Jas.: abbreviation for given name, James (see also above)

Januarius, Ianuarius (Jan): (latin) month of January

Jemmie, Jimmie: fem. nickname for Jemima

Jennie, Jenny: nickname for Jane, Jean, Jennifer or Virginia

Jer.: abbreviation for Jeremiah.

Jeremiah L.: in the South, may be a namesake of Methodist Preacher Jeremiah Lambert

Jerry: nickname for Jeremiah or Gerald

Jhon.: (latin) abbreviation for given name Johannis

Johannis: (latin) given name, John

Jno.: abbreviation for given name, John

Jim, Jimmy: nickname for James

Jocosa: (latin) given name, Joyce

Jos.: abbreviation for Joseph (nickname: Joe)

Josh: nickname for Joseph, Joshua, Josiah (abbrev. Jos. or Joh, although Joh. is sometimes abbrev. for Jonathon)

Julian calendar  . the calendar established by Julius Cesar and used as late as 1751. See calendars

Julius, Iulius (Jul): (latin)

Junius, Iunius (Jun): (latin) month of June

junior  . modern usage of this word following a name (John Combs, Jr.) indicates "son of" an individual by the same name. In earlier times (particularly pre-1800), its use might instead indicate the individual is "the younger" of two individuals with the same name.