「渡る」(wataru) means to cross over something, like a bridge, road, or river. It is an intransitive verb. You often use the particle "を" to indicate the place you are crossing over. For example: 橋を渡る。(Hashi o wataru.) = To cross the bridge.

道や橋などを越えて、反対側へ行くことです。「〜を渡る」。例：道を渡る。