Mean Business Meaning

(idiomatic, used to convey serious intent) To be serious, especially where achieving a specific end against opposition is concerned.

Example: 1895, William Chambers, Robert Chambers, Chambers's journal:
  Say in a week from now, I will undertake to deliver this most marvellous masterpiece, if 'Look here, 'Tony, I mean business, if you don't.
2002, Armando T. Atienza, Shrewd Business Tactics:
  He projects his concern to all employees and he means business when he says the “buck stops here”.