This book summarizes the studies and works integrated in the Manual for the Management of Protected Areas in French-speaking Africa and in the Manual for the Management of Birds and Their Habitats in Coastal Zones, collective works that I directed. The organization of this dictionary is simple. The words are presented in alphabetical order, thus combining definitions of terms used more or less frequently and presentation of concepts governing the functioning of ecosystems or the main concepts of conservation. For each word selected, there is a translation into English in brackets. My aim is for this mass of information to be used quickly and easily. It therefore only exists in pdf format, which allows a very quick search for the words for which a definition is sought. I therefore do not derive any financial benefit from its broadcast, despite the hundreds of hours that were needed to write and review the whole thing.