A good lawyer, an evil neighbour.

The saying links professional legal skill with troublesome conduct in nearby personal life. It suggests that someone adept at arguing claims and rights may become an especially difficult person to live beside.

It is a cynical warning, not a rule about lawyers as people. Its force comes from imagining ordinary neighbourly disagreements turned into formal disputes, where legal knowledge can make conflict more persistent and intimidating.

Use it as a wry comment on a neighbour who is combative, procedural, or quick to threaten legal action. Because it stereotypes lawyers and can insult a real person professionally, reserve it for informal, clearly humorous or critical contexts.