Not ever; not at any time; never, whether past, present, or future.
In no degree; not at all; not a whit; perhaps not, emphatically.
[Never in this use, utilizing the after indefinite article a, is equivalent to no, or nothing, plus in the developed type ne'er a is the origin associated with the dialectal or slang adjectivc nary.
[In this idiom there is a suppressed comparison—‘never (at any other time) so (great, good, much, etc.) as in the case supposed or considered.’ Never, becoming merely emphatic, is now usually replaced by ever.