fasciculi 🔊 Listen to this < /fəˈsɪk yəˌlaɪ/. a fascicle, as of nerve or muscle fibers. a fascicle of a book. noun plural -li (-ˌlaɪ) another name for fascicle (def. 2), fascicule n. pl. fas•cic•u•li (-lī′) A bundle of anatomical fibers, as of muscle.fascicle Share Facebook Twitter Google +