Definition of "Dobbin"

Dobbin

proper noun
1. A surname originating as a patronymic.
2. A pet name given to workhorses, and by extension, a placeholder name used for any workhorse, much like John Q. Public and other such placeholders are used for people.
  Quotations
  […] thou haſt got more haire on thy chin, then Dobbin my phillhorſe has on his taile.
  c. 1596–1598 (date written), William Shakespeare, “The Merchant of Venice”, in Mr. William Shakespeares Comedies, Histories, & Tragedies […] (First Folio), London: […] Isaac Iaggard, and Ed[ward] Blount, published 1623, [Act II, scene ii], page 168