The Collaborative International Dictionary of English v.0.48:

Infinity \In*fin"i*ty\, n.; pl. Infinities. [L. infinitas; pref. in- not + finis boundary, limit, end: cf. F. infinit['e]. See Finite.] [1913 Webster] 1. Unlimited extent of time, space, or quantity; eternity; boundlessness; immensity. --Sir T. More. [1913 Webster] There can not be more infinities than one; for one of them would limit the other. --Sir W. Raleigh. [1913 Webster] 2. Unlimited capacity, energy, excellence, or knowledge; as, the infinity of God and his perfections. --Hooker. [1913 Webster] 3. Endless or indefinite number; great multitude; as an infinity of beauties. --Broome. [1913 Webster] 4. (Math.) A quantity greater than any assignable quantity of the same kind. [1913 Webster] Note: Mathematically considered, infinity is always a limit of a variable quantity, resulting from a particular supposition made upon the varying element which enters it. --Davies & Peck (Math. Dict.). [1913 Webster] 5. (Geom.) That part of a line, or of a plane, or of space, which is infinitely distant. In modern geometry, parallel lines or planes are sometimes treated as lines or planes meeting at infinity. [1913 Webster] Circle at infinity, an imaginary circle at infinity, through which, in geometry of three dimensions, every sphere is imagined to pass. Circular points at infinity. See under Circular. [1913 Webster]The Collaborative International Dictionary of English v.0.48:

Circular \Cir"cu*lar\, a. [L. circularis, fr. circulus circle: cf. F. circulaire. See Circle.] [1913 Webster] 1. In the form of, or bounded by, a circle; round. [1913 Webster] 2. repeating itself; ending in itself; reverting to the point of beginning; hence, illogical; inconclusive; as, circular reasoning. [1913 Webster] 3. Adhering to a fixed circle of legends; cyclic; hence, mean; inferior. See Cyclic poets, under Cyclic. [1913 Webster] Had Virgil been a circular poet, and closely adhered to history, how could the Romans have had Dido? --Dennis. [1913 Webster] 4. Addressed to a circle, or to a number of persons having a common interest; circulated, or intended for circulation; as, a circular letter. [1913 Webster] A proclamation of Henry III., . . . doubtless circular throughout England. --Hallam. [1913 Webster] 5. Perfect; complete. [Obs.] [1913 Webster] A man so absolute and circular In all those wished-for rarities that may take A virgin captive. --Massinger. [1913 Webster] Circular are, any portion of the circumference of a circle. Circular cubics (Math.), curves of the third order which are imagined to pass through the two circular points at infinity. Circular functions. (Math.) See under Function. Circular instruments, mathematical instruments employed for measuring angles, in which the graduation extends round the whole circumference of a circle, or 360[deg]. Circular lines, straight lines pertaining to the circle, as sines, tangents, secants, etc. Circular note or Circular letter. (a) (Com.) See under Credit. (b) (Diplomacy) A letter addressed in identical terms to a number of persons. Circular numbers (Arith.), those whose powers terminate in the same digits as the roots themselves; as 5 and 6, whose squares are 25 and 36. --Bailey. --Barlow. Circular points at infinity (Geom.), two imaginary points at infinite distance through which every circle in the plane is, in the theory of curves, imagined to pass. Circular polarization. (Min.) See under Polarization. Circular sailing or Globular sailing (Naut.), the method of sailing by the arc of a great circle. Circular saw. See under Saw. [1913 Webster]