Did they have dictionaries in the ancient times?
I mean who used the dictionaries? Did authors use them to know how to write?
I don't think it worked this way. But when in the history dictionaries began to be really in use?
For instance, they give approximative dates in some sites, but no mean to know about the diffusion:
Was it a private project from the author? Did every civilizations have their dictionaries? Could it be that some texts have been lost?
Reference:
The oldest known dictionaries were Akkadian Empire cuneiform tablets with bilingual Sumerian–Akkadian wordlists (...)
(early 2nd millennium BC)
http://www.historyofinformation.com/detail.php?id=2090
For Latin:
The oldest Latin Dictionary was compiled by Solomon, bishop of Constance, about the year 1410.
But:
1st cent. BC
Beginnings of ancient Latin lexicography, in works such as the lost Liber glossematorum of Lucius Ateius Philologus.
For Greek:
circa 300 BC:
Philitas of Cos and Simias (or Simmias) of Rhodes make the first extensive learned collections of glosses of ancient Greek epic and dialect words, initiating the Greek lexicographical tradition. Their work only survives in fragments.