broad ‧ en /ˈbrɔːdn $ ˈbrɒːdn/ BrE AmE verb
1 . [transitive] 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 SYN 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 SYN widen :
Mark’s smile broadened.
The council decided to broaden the pavement.
broaden out phrasal verb
if something, especially a river or road, broadens out, it becomes wider SYN widen out :
The river broadens out at this point.