A sanction was a type of action taken by a power against another power, usually as a pressure tool or punishment. The term could also refer to actions taken by governments or organizations against their own, to punish illegal actions.
During the negotions for the Coalition of Planets, in 2155, Tellarites pushed for trade sanctions against the Orions, which they claimed were pirating Tellarite freighters. A Coridan ambassador expressed his people's opposition to these sanctions. (ENT: "Demons")
By 2375, the Federation had ordered sanctions against the Son'a for more than one reason. As a result of sanctions, it was believed that they had stopped raiding planets for slaves. (Star Trek: Insurrection)