Definition of make it one's business
- He's decided to make it his business to bring more affordable housing to the city.
: behave, act
: to begin or seem to begin (an action)
: to cause to happen to or be experienced by someone
: the manner or style in which a thing is constructed
: the physical, mental, or moral constitution of a person
What made you want to look up make it one's business? Please tell us where you read or heard it (including the quote, if possible).