A contronym is a word with two opposite meanings. For example, the word cleave can mean "to cut apart" or "to bind together". This feature is also called enantiosemy,[1][2] enantionymy (enantio- means "opposite"), antilogy or autoantonymy. An enantiosemic term is by definition polysemic.
The coexistence of two opposite meanings in a word is called enantiosemy, and the examples are rather numerous.