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Phrase(s): broaden out
to become wider; to expand. • The river broadened out and became deeper. • The road broadens out here., Phrase(s): broaden something out
to make something wider; to expand something. • Now, broaden this part out a little, so it looks like a cloud, not a painted pillow. • Broaden out the river in your painting so it looks very wide. • The photographic view of the valley can be broadened out by using a different lens.
McGrawhill's American Idioms And Phrasal Verbs