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fi·bril

(fībrəl, fĭbrəl)

1. A small slender fiber or filament.

2. Anatomy A threadlike fiber or filament, such as a myofibril or neurofibril, that is a constituent of a cell or larger structure.

3. A long strand of proteins that are aggregated together in a beta-sheet structure; an amyloid fibril.

[New Latin fibrilla, diminutive of Latin fibra, fiber.]

fibril·lar (-lər), fibril·lar′y (-lĕr′ē) adj.

fibril·lose′ (-lōs′) adj.

Indo-European & Semitic Roots Appendices

Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:

Indo-European Roots

Semitic Roots

The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots.

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