That which is least good in quality or value; the most inferior kind or lowest quality (of an article). Now chiefly as a count noun: a worst score…

That which is most unpleasant, grievous, unfortunate, painful, or hard to bear; a state of things that is most undesirable or most to be dreaded…

The lowest or worst part of something, the dregs; the lowest stratum. Obsolete.

In the superlative with the, as the goldarnedest. The biggest or most impressive; the most amazing; (also) the worst or most unpleasant. Cf. goddamned…