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]
(..) men outside your walls. They'll be corpses when Tywin Lannister gets here. Don't try and frighten me, Lady Stark. Your husband's in a cell beneath the Red Keep and your son's got no fur to keep his balls warm. You swore an oath to my father. Oh, yes, I said some words. (..)2011 TvShow: Game of Thrones Title: Baelor Season: 1 Episode 9