fence out
To create a barrier so that someone or an animal can't access something else. A noun or pronoun can be used between "fence" and "out." I think fencing out the deer is the only way we'll get them to stop snacking on our vegetable garden.
fence (someone or an animal) out
to keep someone or an animal out with a fence or barrier. We decided that living in the woods was satisfactory only if we fenced the wildlife out. We had to fence out the deer. We hoped we had fenced prowlers out with the tall electric fence.