octagon

The word 'octagon' is a direct borrowing from the Latin octagōnon, which itself originates from the Greek oktágōnon, a combination of oktō (eight) and gōnía (angle). This construction follows a classical pattern for naming geometric shapes, where a numerical prefix is attached to the suffix '-gon'. The logic is perfectly literal and mathematical: an eight-angled figure. The term entered English in the late 16th century, retaining its precise geometric meaning without significant semantic shift, serving as a clear example of how Greek components were adopted into scientific and mathematical vocabulary.

Structure: octa (eight) + gon (angle) - octa: From Greek oktō, meaning "eight". A combining form used in English to denote the number eight. - gon: From Greek gōnia, meaning "corner" or "angle". A combining form used in geometry to denote a figure with a specified number of angles.