Jnr

from WordNet (r) 3.0 (2006)

Jnr
    n 1: a son who has the same first name as his father [syn:
         {Junior}, {Jr}, {Jnr}]

from The Collaborative International Dictionary of English v.0.48

Jnr \Jnr.\ n.
   Abbreviation for Junior, used after a name by a son who has
   the same first and last name as his father; -- less commonly
   used than {Jr.}

   Syn: Junior, Jr.
        [WordNet 1.5]