How to say 'vacation' in Spanish: Vacacion. Go ahead, you try it. If you want to say something like 'I need a vacation to the Bahamas', you would say, "Necesito una vacacion a las Bahamas." Go ahead, you try it. If I ask you, "Do you need a vacation to the Bahamas?" you would say, "Si, necesito una vacacion a las Bahamas." Go ahead, try it again.
Remember, the plural in Spanish for 'vacation' is 'vacaciones', with an 'es' at the end of the word. Go ahead, try that one. Vacaciones; that's how to say 'vacation' or 'vacations' in Spanish.