out of nowhere
US /aʊt əv ˈnoʊˌwɛr/
UK /aʊt əv ˈnoʊˌwɛr/

1.
突然, 出乎意料地
appearing or happening suddenly and unexpectedly
:
•
The car came out of nowhere and almost hit me.
那輛車突然出現,差點撞到我。
•
He just started shouting out of nowhere.
他突然開始大喊大叫。
突然, 出乎意料地
appearing or happening suddenly and unexpectedly