An Universal Etymological English Dictionary was a dictionary compiled by Nathan Bailey (or Nathaniel Bailey) and first published in London in 1721.
In compiling his dictionary, Bailey borrowed greatly from John Kersey's Dictionarium Anglo-Britannicum (1706), which in turn drew from the later editions of Edward Phillips's The New World of English Words.
A very high percentage of the etymologies he does give are consistent with what is in today's English dictionaries.
Volume II, almost 900 pages, has some duplication or overlap with the primary volume, but mostly consists of extra words of lesser circulation.
The title page of the supplementary volume says it contains "An additional collection of words (not in the first volume) ALSO an explication of hard and technical words in all arts and sciences... ALSO words and phrases contained in our ancient charters, statutes, and processes at Law ALSO the theology and mythology of the Egyptians, Greeks and Romans...."