broaden out

broaden out

to become wider; to expand. The river broadened out and became deeper. The road broadens out here.
See also: broaden, out

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.
See also: broaden, out
References in classic literature ?
Sometimes the tunnel was so narrow that the wheels of the buggy grazed the sides; then it would broaden out as wide as a street; but the floor was usually smooth, and for a long time they travelled on without any accident.