1. One who cultivates orchids; an orchidist: Grace thought that orchids were wonderful plants and easy to care for, so she became an orchideacean and devoted herself to growing many kinds of orchids.
2. A plant of the family Orchidaceae: Lisa found 20 different types of orchidaceans in a botany book she was reading and chose the Cattleya and the Dendrobium that she wanted to buy.