可逆

可逆	kě nì	reversible / (math.) invertible
可	kě	(prefix) can; may; able to; -able / to approve; to permit / to suit / (particle used for emphasis) certainly; very / but; however
可	kè	used in 可汗
逆	nì	contrary / opposite / backwards / to go against / to oppose / to betray / to rebel