eye-literate

How you might feel when you want to use a word in conversation that you're familiar with in reading and writing, you know perfectly well what it means, but you've never heard it spoken, and have no idea how to pronounce it.

"It doesn't matter how many times you click on Font Color. Changing red text to red again won't make a difference. It's eye-dem-... id-em-..." (thinking, "How the *$%^& do you pronounce 'idempotent'??? Guess that makes me eye-literate.")