Merriam-Webster's Collegiate® Dictionary, 11th Edition
DITTO
I. noun (plural dittos) see: diction
Date: circa 1639
a thing mentioned previously or above, a ditto mark,
II. adjective
Date: 1776
having the same characteristics ; similar ,
III. adverb
Date: 1706
as before or aforesaid ; in the same manner,
IV. transitive verb
Date: 1725
to repeat the action or statement of, to copy (as printed matter) on a duplicator