iota subscript

iota subscript (plural iotas subscript or iota subscripts)

1. (Greek orthography) A small iota written below an alpha, eta or omega – e.g. in ᾠδή (ōidḗ) – representing a vocalic offglide that was pronounced in early Ancient Greek, but later became silent; invented in the Middle Ages in order to mark those vowels which would originally have had such an offglide.

• iota adscript