to increase something such as your knowledge, experience, or range of activities:
The course helps school-leavers broaden their knowledge of the world of work.
I'd like to work abroad to broaden my horizons (=learn, experience, or attempt new things).
Travel broadens the mind (=helps you to understand and accept other people's beliefs, customs etc).
2 [intransitive and transitive]
to affect or include more people or things, or to make something affect or include more people or things [= widen, expand]:
Mr Mates said the party must broaden its appeal to younger voters.
Flynn's appeal broadened as the campaign continued into the summer months.
I want to broaden the discussion to other aspects of the problem.
3 [intransitive and transitive]
to make something wider or to become wider [= widen]:
Mark's smile broadened.
The council decided to broaden the pavement.
broaden outphrasal verb
The river broadens out at this point.