abishag

From Hebrew אבישג‎ (“Avishag”, literally “Father of error” or “the Father wanders”), from אבי‎ (avi, “father of; my father”) and שגג‎ (shagag, “to go astray; to err; to sin”).

abishag (plural abishags)

1. (archaic, thieves' cant) The illegitimate child of an unmarried woman and a married man.

• bastard, love-child

• “abishag” in Albert Barrère and Charles G[odfrey] Leland, compilers and editors, A Dictionary of Slang, Jargon & Cant, volume I (A–K), Edinburgh: The Ballantyne Press, 1889–1890, page 5.
• Eric Partridge, A Dictionary of the Underworld, London, Macmillan Co., 1949