Columnar

[Sarah]

Formed in columns; having the form of a column or columns; likethe shaft of a column. Columnar epithelium (Anat.), epithelium inwhich the cells are priismatic in form, and set upright on thesurface they cover.-- Columnar structure (Geol.), a structure consisting of more orless regular columns, usually six-sided, but sometimes with eight ormore sides. The columns are often fractured transversely, with a cupjoint, showing a concave surface above. This structure ischaracteristic of certain igneous rocks, as basalt, and is due tocontraction in cooling.