He won't do any work that he considers 'beneath' him. [=work that he thinks is not good enough for a person of his social class]
He thought washing dishes was 'beneath his dignity'. [=he thought that he was too good or important to wash dishes]
The chair sagged 'beneath' [='under, underneath'] his weight. [=his weight caused the chair to sag]
(..) to go through with it. I'm gonna burn this fucking place down. and I'm gonna end this nightmare. Why don't you just run away? Go hide beneath some rock somewhere. You know, You're great at that. Oh, shit! Where the fuck did she go? David. (..)2013 Evil Dead