a tubular aggregate of protein subunits that forms structures, such as the mitotic spindle or the cilia of animal cells or of protozoans, in which the protein interacts with other proteins to generate various cellular movements
microtubule in American English
(ˌmaɪkroʊˈtuˌbjul)
noun
any of a number of small, hollow filaments, composed of long strands of tubulins, that are found in animal or plant cells and are associated esp. withcell structure and movement and with mitosis