Iota /(?)/

I·o·ta

Iota

n.
  1. The ninth letter of the Greek alphabet (ι) corresponding with the English i.
  2. A very small quantity or degree; a jot; a particle.
    They never depart an iota from the authentic formulas of tyranny and usurpation.

Phrases & Compounds
Iota subscript
iota written beneath a preceding vowel, as a,, h,, w,, -- done when iota is silent.