"having the form of a column; of or pertaining to a column," 1728, from Late Latin columnaris "rising in the form of a pillar," from columna "column" (see column).
Entries linking to columnar
column n.
mid-15c., "a pillar, long, cylindrical architectural support," also "vertical division of a page," from Old French colombe (12c., Modern French colonne "column, pillar"), from Latin columna "pillar," collateral form of columen "top, summit," from PIE root *kel- (2) "to be prominent; hill."
In the military sense "formation of troops narrow in front and extending back" from 1670s, opposed to a line, which is extended in front and thin in depth. Sense of "matter written for a newspaper" (the contents of a column of type) dates from 1785.