/plas"tid/ , n. Cell Biol.
a small, double-membraned organelle of plant cells and certain protists, occurring in several varieties, as the chloroplast, and containing ribosomes, prokaryotic DNA, and, often, pigment.
[ 1875-80; Plastide plastid-, s. of plástis, fem. deriv. of plástes modeler, creator, deriv. of plássein to form ]