Heptagonal

Part of speech: adjective

Pronunciation: /hɛpˈtæɡənəl/

Definitions

1. Pertaining to a geometric figure characterized by seven straight sides and angles, this term relates to the study of polygons in mathematics
2. Referring to objects or structures exhibiting seven-fold symmetry, it encompasses aspects of design and geometry alike
3. Relating to any shape or form that features seven angles and sides, this term often appears in discussions of geometric properties and architectural designs

Etymology: "Heptagonal" is built from two parts that go back to ancient Greek. The first, "hepta", means "seven," the same root that appears in "heptathlon" and the seven-day week's Greek numerals. The second, "gon", means "angle" or "corner," which gives us "polygon," a shape with many corners. Put together, "heptagon" names a seven-sided figure, and English has used it since the 16th century. "Heptagonal" is the adjective made from that noun by adding "-al," a common English suffix meaning "relating to" or "having the nature of," as in "triangular" or "rectangular." So the word describes anything that has the form of a heptagon, whether a coin, a window pane, or a cross-section of a crystal. It is a straightforward formation with no surprises in its history: the shape came first, the noun followed, and the adjective was built from the noun.