1 [transitive, intransitive] to make sure that somebody/something is not harmed, injured, damaged, etc. protect somebody/something/yourself (against/from something) Troops have been sent to protect aid workers against attack. They huddled together to protect themselves from the wind. Our aim is to protect the jobs of our members. Each company is fighting to protect its own commercial interests. protect (against/from something) a paint that helps protect against rust2 [transitive, usually passive] protect something to introduce laws that make it illegal to kill, harm or damage a particular animal, area of land, building, etc. a protected area/species The plant is protected under the Wildlife and Countryside Act.