Shechem alone had defiled Dinah, but [Jacob](rc://en/tw/dict/bible/names/jacob)'s sons considered Shechem's entire family and everyone in the city responsible for this act.
This means that Shechem had greatly dishonored and disgraced Dinah by forcing her to sleep with him. See how you translated "defiled" in [Genesis 34:5](./04.md).