The Collaborative International Dictionary of English v.0.48:

Shaggy \Shag"gy\, a. [Compar. Shaggier; superl. Shaggiest.]
   [From Shag, n.]
   Rough with long hair or wool.
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         About his shoulders hangs the shaggy skin. --Dryden.
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   2. Rough; rugged; jaggy. --Milton.
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            [A rill] that winds unseen beneath the shaggy fell.
                                                  --Keble.
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