1
general::
Also, from the outset. At the start, from the start. For example, He wanted to explain his position from the outset, but there wasn't time, or At the outset the problem seemed simple, but then it became quite complicated. The noun outset is rarely heard today except in these phrases. [Mid-1700s]
American Heritage Idioms
2
general::
Phrase(s): at the outset
Fig. at the very beginning. • At the outset, we were told everything we had to do. • I learned at the outset of the project that I was to lead it.
McGrawhill's American Idioms And Phrasal Verbs