What is "unkinder"

Usage examples of "unkinder".

She looked like a child who has suffered more reverses in a single day than ever before in living memory, and is now poised between refusal and acceptance of the fact that life might be significantly worse than she thought, that life was unkinder in its essence, and no one had given her fair warning.

Although it sounded like one of the engineer's unkinder wisecracks, it had been made entirely without malice - indeed, with sympathy.