moving from one place to another and back again; "he traveled back and forth between Los Angeles and New York"; "the treetops whipped to and fro in a frightening manner"; "the old man just sat on the porch and rocked back and forth all day"
become broader or wider or more extensive; "The road widened"
make wider; "widen the road"
extend in scope or range or area; "The law was extended to all citizens"; "widen the range of applications"; "broaden your horizon"; "Extend your backyard"