Despite my opponent's personal attacks against me, I refuse to 'stoop to his level'. [=I refuse to behave as badly as he has by attacking him personally]
She would never 'stoop' to lying. [=she would never lie; she is too good a person to lie]
His shoulders are 'stooped'. [=his shoulders are bent forward]
(..) Will you give me that? Boy, I hate these things. - Did you ever see a knife fight? - No. Anybody here ever see a knife fight? Well, I have. You know, on my back stoop, the lot across the street, back yard. Switchblades came with the neighbourhood. Funny I never thought of it before. (..)1957 12 Angry Men