cut off nose
劓 centers on the act of cutting off the nose, a specific historical punishment. The meaning is narrow and concrete, with no common abstract extensions.
劓 combines 鼻 (nose) and 刂 (knife), directly depicting the punishment of cutting off the nose. The structure is transparently semantic.
A nose 鼻 with a knife 刂 beside it: the knife is about to cut off the nose.
For ギ, imagine a guilty person about to lose their nose: guilty -> ギ, and the knife 刂 cuts the nose 鼻.
cutting off the nose (form of punishment in ancient China)