The word "fibrous" means something that is made up of or contains fibers, which are thin and long strands, similar to threads or strings. Full definition
Muscle is defined as a band or bundle of fibrous tissue in a human or animal body that has the ability to contract to produce a particular movement. (varietytrainer.com)
The cruciate ligaments are two bands of fibrous tissue located in each knee joint. (glenerinanimalhospital.com)