fibrous

1. Having, consisting of, or resembling fibers.
2. Full of sinews; tough.

Definition: stringy
Antonyms: nonfibrous

Composed of or characterized by fibroblasts, fibrils, or connective tissue fibers.

Composed of or containing fibers.

• f. bone — see woven bone.
• cardiac f. skeleton — includes a ring around each of the atrioventricular valves and each of the great arteries leaving the heart; between the rings are the right and left fibrous trigones.
• f. dysplasia — localized overgrowth of fibrous tissue in bone.
• f. feeds — feeds high in fiber, cellulose and lignin.
• f. growth plates — growth plates composed of fibrocartilage such as that for the tibial tubercle.
• f. histiocytoma — see malignant fibrous histiocytoma.
• f. hyperplasia — indistinguishable clinically from fibromatous epulis.
• f. joint — 1. a joint whose bony elements are united with fibrous tissue. See suture (1), syndesmosis.
— 2. stiffness in a joint due to fibrous tissue reaction in the joint capsule and other supporting structures.
• f. osteodystrophy — see osteodystrophia fibrosa.
• f. rings — bands of fibrous tissue surrounding the semilunar valves of the aorta and pulmonary artery and the atrioventricular valves.
• f. tissue — the common connective tissue of the body, composed of yellow or white parallel elastic and collagen fibers.

The adjective has 2 meanings:

Meaning #1: having or resembling fibers especially fibers used in making cordage such as those of jute
  Synonym: hempen

Meaning #2: (of meat) full of sinews; especially impossible to chew
  Synonyms: sinewy, stringy, unchewable