1. Immeasurably or incalculably minute.
2. Mathematics. Capable of having values approaching zero as a limit.

1. An immeasurably or incalculably minute amount or quantity.
2. Mathematics. A function or variable continuously approaching zero as a limit.

[From New Latin īnfīnītēsimus, infinite in rank, from Latin īnfīnītus, infinite. See infinite.]

The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.