column vs columnar

column is a noun but columnar is not a noun.

Word	Noun	Adjective	Verb	Adverb
column	Yes	No	No	No
columnar	No	Yes	No	No

column (noun)	columnar (noun)
(architecture) a tall vertical cylindrical structure standing upright and used to support a structure
a vertical cylindrical structure standing alone and not supporting anything (such as a monument)
a vertical glass tube used in column chromatography; a mixture is poured in the top and washed through a stationary substance where components of the mixture are adsorbed selectively to form colored bands
any tubular or pillar-like supporting structure in the body
an article giving opinions or perspectives
a page or text that is vertically divided
a line of units following one after another
a vertical array of numbers or other information
anything that approximates the shape of a column or tower

column (adjective)	columnar (adjective)
	characterized by columns
	having the form of a column