Anglo-French fitz, from Old French fils, from Latin filius "son of" (see filial); used regularly in official rolls and hence the first element of many modern surnames; in later times used of illegitimate issue of royalty.
Examples from the Web for fitz
In 1961, Hulanicki married Stephen “Fitz” Fitz-Simon, a young British businessman whom she met at a party in London.Barbara Hulanicki, Queen of Fast Fashion
October 15, 2014
Hunkered down in a bunker, she, Mellie, and Fitz argue over what details about their relationship they want to make public.
His response to her is about Fitz, like wow, what has he done to you.
First Lady Mellie (Bellamy Young) and Fitz reconcile—because of the whole rape thing—and we learn the son is actually his.The Explosive ‘Scandal’ Finale Was Its Best Episode Yet
April 18, 2014
The artist formerly known as President Fitz is slated to bring the infamous polygamist to life in an upcoming Lifetime movie.Ke$ha Leaves Rehab, Miley Cyrus Poses With Sex Toy
March 7, 2014
Some asserted that the whole thing was a puff, got up by Fitz.The Confessions of Harry Lorrequer, Complete
Charles James Lever (1806-1872)
This was not a very successful commencement of economy; but Mrs. Fitz.Tales Of The Trains
Charles James Lever
Fitz can be ca'm whin they'se annything to be ca'm about, but he can't wait.Mr. Dooley in Peace and in War
Finley Peter Dunne
If this piece succeeds, it can't be played every night—let Fitz.The English Spy
"I believe he's got appendicitis," announced Fitz, gazing up at us.Pluck on the Long Trail
Edwin L. Sabin