Adjective
Having, or approaching, the shape of a rhomboid.
Source: Webster's dictionaryrhomboidal shapes Source: Internet
Blade strength was achieved by welding together strips, in which case the sword had a channel down the center, or by fashioning a single piece of high-carbon steel, rhomboidal in cross-section. Source: Internet
It has a rhomboidal shape, with four towers: two quadrangular at the corners and the other two are connected by curtains and are cylindrical. Source: Internet