/hɔːrs treɪdɪŋ/ – noun
Definition: Đàm phán, thương lượng.
A more thorough explanation: negotiations between parties that provide both parties with advantages. The term is sometimes used to suggest that the discussions are difficult, secret, and possibly dishonest or involve compromises that some people might find unacceptable.
Example: He said that the UN must abandon the “secret deals and horse trading” that govern the selection of its Secretary-General.