[ noun ] any of various small particles in the cytoplasm of the cells of plants and some animals containing pigments or starch or oil or protein <noun.plant>
Plastid \Plas"tid\, Plastide \Plas"tide\, n. [Gr. ?, ?, a creator.] 1. (Biol.) A formative particle of albuminous matter; a monad; a cytode. See the Note under {Morphon}. [Archaic] --Haeckel.
2. (Bot.) any of several types of minute granules found in the protoplasm of vegetable cells, having their own membrane, robosomes, and DNA. Among plant cells the most common are {chloroplasts}, which contain the chlorophyll and the photosynthetic machinery of the cell. They are divided by their colors into three classes, chloroplastids, chromoplastids, and leucoplastids. [1913 Webster +PJC]