[cir.cu.lar] adj [ME circuler, fr. MF, fr. LL circularis, fr. L circulus circle] (15c) 1 a: having the form of a circle: round b: moving in or describing a circle or spiral
2. a: of or relating to a circle or its mathematical properties "a ~ arc" b: having a circular base or bases "a ~ cylinder"
3: circuitous, indirect
4: marked by or moving in a cycle
5: being or involving reasoning that uses in the argument or proof a conclusion to be proved or one of its unproved consequences
6: intended for circulation -- cir.cu.lar.i.ty n -- cir.cu.lar.ly adv -- cir.cu.lar.ness n
[2]circular n (1789): a paper (as a leaflet) intended for wide distribution