Definition of "impish"

Wild-eyed youngsters they were, with matted hair and little broad-nosed impish faces, covered (as some children are covered even nowadays) with a delicate down of hair.

1897, H. G. Wells, chapter 1, in A Story of the Stone Age‎, archived from the original on 9 March 2012

But the antics of Mr. Moore, though impish and impudent, are, after all, so amusing and so graceful that the governess, it is said, sometimes hides behind a tree to watch.

1942, Virginia Woolf, chapter 20, in The Death of the Moth, and other essays‎, archived from the original on 24 February 2011