The endoplasmic reticulum is defined as a series of folded membranes in the cells which are associated with protein synthesis, storage and the movement of cellular materials.
An example of the endoplasmic reticulum is the place that steroids are stored in the cells for later use.
a system of folded membranes, channels, and flattened sacs in the cytoplasm of eukaryotic cells, involved in the synthesis, storage, and transport of various substances necessary to cell function: as the point of attachment for ribosomes, it is especially associated with protein synthesis
A membrane network within the cytoplasm of cells involved in the synthesis, modification, and transport of cellular materials.
An organelle consisting of a network of membranes within the cytoplasm of eukaryotic cells that is important in protein synthesis and folding and is involved in the transport of cellular materials. The endoplasmic reticulum can be continuous in places with the membrane of the cell nucleus. The function of the endoplasmic reticulum can vary greatly with cell type, and even within the same cell it can have different functions depending on whether it is rough or smooth.
See more at cell