last-place vs worst

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

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

last-place (noun)	worst (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

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

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

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