Meaning of CIRCULAR in English

[] 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 -- n -- adv -- n

[2]circular n (1789): a paper (as a leaflet) intended for wide distribution

Merriam-Webster English vocab.      Английский словарь Merriam Webster.