IOTA

I‐o″ta (?), n. [[L., fr. Gr. ιὠ̑τα. See Jot.]] 1. 1. The ninth letter of the Greek alphabet (ι) corresponding with the English i.
2. 2. A very small quantity or degree; a jot; a particle.
They never depart an iota from the authentic formulas of tyranny and usurpation. Burke. Iota subscript (Gr. Gram.), iota written beneath a preceding vowel, as ᾳ, ῃ, ῳ, — done when iota is silent.