stratify vs stratum

stratify is not a noun while stratum is a noun.

Word	Noun	Adjective	Verb	Adverb
stratify	No	No	Yes	No
stratum	Yes	No	No	No

stratify (noun)	stratum (noun)
	an abstract place usually conceived as having depth
	a subpopulation divided into a stratified sampling
	people having the same social, economic, or educational status
	one of several parallel layers of material arranged one on top of another (such as a layer of tissue or cells in an organism or a layer of sedimentary rock)

stratify (verb)	stratum (verb)
render fertile and preserve by placing between layers of earth or sand
form layers or strata
form, arrange, or deposit in layers
divide society into social classes or castes
develop different social levels, classes, or castes