fell vs putting to death

fell and putting to death both are nouns.

Word	Noun	Adjective	Verb	Adverb
fell	Yes	Yes	Yes	No
putting to death	Yes	No	No	No

As nouns, putting to death is a hypernym of fell; that is, putting to death is a word with a broader meaning than fell:

Other hypernyms of fell include kill, killing.

fell (noun)	putting to death (noun)
the act of felling something (as a tree)	the act of terminating a life
seam made by turning under or folding together and stitching the seamed materials to avoid rough edges
the dressed skin of an animal (especially a large animal)

fell (adjective)	putting to death (adjective)
(of persons or their actions) able or disposed to inflict pain or suffering

fell (verb)	putting to death (verb)
cause to fall by or as if by delivering a blow
sew a seam by folding the edges
pass away rapidly