Circinal

Part of speech: adjective

Definitions

1. Having the quality of being circular or curling in form
2. Describing a structure that exhibits coiling or spiral characteristics in nature
3. Characterized by a round or ring-like shape ; exhibiting a winding or coil-like structure

Etymology: "Circinal" comes from Latin "circinus," the word for a pair of compasses, the instrument used to draw circles. The Romans used "circinus" for that drawing tool and, by extension, for anything shaped like a circle. English took the Latin root and attached the adjectival suffix "-al," producing a term that describes things arranged in a circle or coiled into one. The suffix does most of the work here. The "-al" ending is the same one found in words like "national" or "vertical," and it turns a noun into an adjective meaning "relating to" or "having the nature of" that noun. So "circinal" means, in effect, "having the character of a pair of compasses," which points naturally to the curved, circling shape the instrument makes when it sweeps through space.