A feature on many smartphones, commonly referred to as "Autocorrect".
I'd like to use "autofail" in a sentence, but every time I type it in, it gets autocorrected to "autocorrect".
To be so inadequate that one receives an automatic failure.
When one has done so poorly from the beginning that redemption of dignity, self-worth and/or passing grades is hopeless.
My essay's introduction was so convoluted that she'll read it and autofail me.