Chapter Twelve Magic is Might As August wore on, the square of unkempt grass in the middle of Grimmauld Place shriveled in the sun until it was brittle and brown.
His long white candyfloss hair was dirty and unkempt.
The longer Harry looked at Neville, the worse he appeared: One of his eyes was swollen yellow and purple, there were gouge marks on his face, and his general air of unkemptness suggested that he had been living rough.
There are no more uses of "unkempt" in the book.
Show samples from other sources
This kid has long, unkempt hair and a hardened look about him.
Neal Shusterman -- Unwind
With his dark unkempt hair, his unlined face, he looked no more than twenty-five.