pucker

To pinch or wrinkle (especially a body part); to squeeze inwardly, to dimple or fold.

Now the skin was puckered into a million wrinkles, and on the shapeless face was the stamp of unutterable age.

1893, Arthur Conan Doyle, "The Adventure of the Crooked Man". He had a very dark, fearsome face, and a gleam in his eyes that comes back to me in my dreams. His hair and whiskers were shot with gray, and his face was all crinkled and puckered like a withered apple.

A fold or wrinkle.

The mouth was compressed, and on either side of it two tiny wrinkles had formed themselves in her cheeks. An infinity of slightly malicious amusement lurked in those little folds, in the puckers about the half-closed eyes, in the eyes themselves, bright and laughing between the narrowed lids.

A state of perplexity or anxiety; confusion; bother; agitation.

What a pucker everything is in!" said Bathsheba, discontentedly when the child had gone. "Get away, Maryann, or go on with your scrubbing, or do something! You ought to be married by this time, and not here troubling me!"

The anus.

[…]she felt a pressure at her asshole, a cock pressing against her pucker, trying to slide in.