back someone up
phrasal verb with back verb uk/bæk/ us/bæk/
B2 支持,帮助(某人)
to support or help someone
My family backed me up throughout the court case. 打官司期间,我的家人一直在支持我。
C2 为(某人)作证
to say that someone is telling the truth
Honestly, that's exactly what happened - Claire will back me up. 实话实说,这就是当时的情况——克莱尔会为我作证。
Will you back me up if I say that I never saw him? 如果我说从未见过他,你会为我作证吗?