in someone's debt
idiomPart ofdebt
in someone's debt — idiom
1. feeling grateful to someone because of the help or kindness they have given you,
1.idiom
Definition
feeling grateful to someone because of the help or kindness they have given you, with a sense of moral obligation to return the favor
Example
After Hannah helped him find a job, Brandon said he would always be in her debt.
Nala told the rescue team that she was forever in their debt for saving her son.