وَلَا يُجْزِئُ فِي الْهَدْيِ مَقْطُوعُ الْأُذُنِ أَوْ أَكْثَرِهَا، وَلَا مَقْطُوعُ الذَّنَبِ.
Translation: An animal with a cut-off ear, most of its ear missing, or its tail cut off does not qualify.
Maqtū‘ means cut off, and aktharihā means most of the ear.
The ruling targets substantial, disqualifying loss. A slight scratch should not be assumed identical to loss of most of an ear; precise borderline cases require specialist assessment.