Welche Bedeutung steckt hinter der hier vorgestellten Vokabel aus dem Bereich Talking with colleagues?

Rachel: 'Uh-oh, you look really angry...' Sarah: 'I am, believe me. My boss thwarted my plans to leave the office early. Now I've missed my son's football match.'

to thwart

Do you know what it means?

• to stop a plan from being successful
• to postpone an event for a week
• to speak badly of