COLUMNAR
columnar
(adjective) characterized by columns; “columnar construction”
columniform, columnar, columnlike
(adjective) having the form of a column; “trees with columniform trunks”; “columnar forms”; “a columnlike tree trunk”
Source: WordNet® 3.1
Etymology
Adjective
columnar (not comparable)
Having the shape of a column.
Constructed with columns.
Source: Wiktionary
Co*lum"*nar, a. Etym: [L. columnaris, fr. columna.]
Definition: Formed in columns; having the form of a column or columns; like
the shaft of a column. Columnar epithelium (Anat.), epithelium in
which the cells are priismatic in form, and set upright on the
surface they cover.
– Columnar structure (Geol.), a structure consisting of more or
less regular columns, usually six-sided, but sometimes with eight or
more sides. The columns are often fractured transversely, with a cup
joint, showing a concave surface above. This structure is
characteristic of certain igneous rocks, as basalt, and is due to
contraction in cooling.
Source: Webster’s Unabridged Dictionary 1913 Edition