"Vacation" is the Engpsh word for "假期" (jiàqī). It comes from the Middle French word "vacacion" which means "freedom or release from duty or business."
For example:
"I'm going on vacation next week." (我下周要去度假。)
"They saved up all year for their dream vacation." (他们一年都在为梦想假期而存钱。)
"I need a vacation from my vacation." (我需要一个假期休息假期。)