1. the branch of mathematics that is concerned with limits and with the differentiation and integration of functions;

[syn: calculus, infinitesimal calculus]

The Collaborative International Dictionary of English v.0.48:

Infinitesimal \In`fin*i*tes"i*mal\, a. [Cf. F. infinit['e]simal, fr. infinit['e]sime infinitely small, fr. L. infinitus. See Infinite, a.] Infinitely or indefinitely small; less than any assignable quantity or value; very small. [1913 Webster] Infinitesimal calculus, the different and the integral calculus, when developed according to the method used by Leibnitz, who regarded the increments given to variables as infinitesimal. [1913 Webster]WordNet (r) 3.0 (2006):

infinitesimal calculus n 1: the branch of mathematics that is concerned with limits and with the differentiation and integration of functions [syn: calculus, infinitesimal calculus]