Definition of "unduly"

The departure was not unduly prolonged. In the road Mr. Love and the driver favoured the company with a brief chanty running. “Got it?—No, I ain't, 'old on,—Got it? Got it?—No, 'old on sir.”

1922, Ben Travers, chapter 5, in A Cuckoo in the Nest

It was a casual sneer, obviously one of a long line. There was hatred behind it, but of a quiet, chronic type, nothing new or unduly virulent, and he was taken aback by the flicker of amazed incredulity that passed over the younger man's ravaged face.

1963, Margery Allingham, chapter 8, in The China Governess‎