worst vs last-place

worst is a noun but last-place is not a noun.

Word	Noun	Adjective	Verb	Adverb
worst	Yes	Yes	Yes	Yes
last-place	No	Yes	No	No

worst (noun)	last-place (noun)
the weakest effort or poorest achievement one is capable of
the greatest damage or wickedness of which one is capable
the least favorable outcome

worst (adjective)	last-place (adjective)
(superlative of `bad') most wanting in quality or value or condition	lowest in rank or importance

worst (verb)	last-place (verb)
defeat thoroughly

worst (adverb)	last-place (adverb)
to the highest degree of inferiority or badness