knickknack vs article

knickknack and article both are nouns.

Word	Noun	Adjective	Verb	Adverb
knickknack	Yes	No	No	No
article	Yes	No	Yes	No

As nouns, article is a hypernym of knickknack; that is, article is a word with a broader meaning than knickknack:

knickknack (noun)	article (noun)
miscellaneous curios	one of a class of artifacts
a small inexpensive mass-produced article	nonfictional prose forming an independent part of a publication
	(grammar) a determiner that may indicate the specificity of reference of a noun phrase
	a separate section of a legal document (as a statute or contract or will)

knickknack (verb)	article (verb)
	bind by a contract; especially for a training period