8e948578_l_Verbs___Common_Phrasal_Verbs__Phrasal_Verb
[Meaning] To give support or encouragement To make a copy of (file, program, etc.) [Example] I’m going to be very strict with him. I hope you’ll back me up on this? You should back up all your computer files in a secure location. [Phrasal Verb] 
back up
An Extensive List of Phrasal Verbs | Common Phrasal Verbs
Phrasal Verb