0 to start an activity with a particular aim: --
[ + to infinitive ] They set out to discover a cure for cancer.
She set out with the aim of becoming the youngest ever winner of the championship.
2 to start an activity with a particular aim: --
set out to do sth He set out to design software that would be accessible to employees outside the accounting department.
Some people set out with the deliberate intention of running their own business, others stumble into it.