in the event that
US /ɪn ðɪ ɪˈvent ðæt/
UK /ɪn ðɪ ɪˈvent ðæt/

1.
万一, 如果
if a particular thing happens
:
•
In the event that it rains, we will move the party indoors.
万一下雨,我们就把派对移到室内。
•
You will be notified in the event that there are any changes to the schedule.
如果时间表有任何变动,您将收到通知。