sliver vs dissever

sliver is a noun but dissever is not a noun.

Word	Noun	Adjective	Verb	Adverb
sliver	Yes	No	Yes	No
dissever	No	No	Yes	No

As verbs, dissever is a hypernym of sliver; that is, dissever is a word with a broader meaning than sliver:

Other hypernyms of sliver include carve up, divide, separate, split, split up.

sliver (noun)	dissever (noun)
a thin fragment or slice (especially of wood) that has been shaved from something
a small thin sharp bit of wood or glass or metal

sliver (verb)	dissever (verb)
break up into splinters or slivers	separate into parts or portions
form into slivers
divide into slivers or splinters