do one's business

noun

1. one's work, occupation, or profession
2. a special task, duty, or function
3. rightful concern or responsibility: no one's business but his own
4. a matter, affair, activity, etc.: the business of packing for a trip
5. the buying and selling of commodities and services; commerce; trade
6. a commercial or industrial establishment; store, factory, etc.
7. the trade or patronage of customers
8. commercial practice or policy
9. a bit of action in a drama, as pouring a drink, intended to establish character, take up a pause in dialogue, etc.

Origin: ME bisinesse < OE bisignes: see busy & -ness

adjective

1. of or for business
2. Bridge designating a double intended to penalize one's opponents