Essentially means at bottom, when you strip away the details. Essentially the same, essentially finished, essentially a rewrite.
It is a hedge that sounds like a clarification, and essentially finished usually means not finished. Used honestly it points at what a thing really is rather than what it is called, which is a useful move in an argument.
1adverbessentiallyAt bottom, when you strip away the details.
“The two phones are essentially the same, apart from the colour.”
essentially is a hedge.
Latin
essentiālis
English
essential
English, today
essentially
From essential + -ly. essential Borrowed from Latin essentiālis. From Latin essentiālis, from Latin essentia (“being, essence”).
Etymology from Wiktionary, CC BY-SA