semi-retractile

They also had skin like soft but armor-tough gray leather, an ovoid head with bulges at top and sides set more horizontally on the short neck than a human's, with small eyes, slit nostrils, lipless shark-toothed mouth, and no external ears -- but except for those and semi-retractile claws on their hands, the biologists insisted that Traiti were so much like humans it ought to indicate a common ancestor somewhere.

Fearful Symmetry A Terran Empire novel Ann Wilson

Their bodies are human-looking, as are the hands (with the exception of semi-retractile claws instead of nails), although their skin is medium gray in color and as tough as leather armor despite its softness.

Concordance A Terran Empire concordance Ann Wilson

It certainly in some degree resembles the cat externally, and it has also semi-retractile claws, but in greater measure it belongs to the Arctoidea.

Natural History of the Mammalia of India and Ceylon Robert Armitage Sterndale 1870

The feet are five-toed, webbed; pads bald; claws semi-retractile; tail very long, with from thirty-six to thirty-eight vertebrae; the pupil of the eye is linear and erect.

Natural History of the Mammalia of India and Ceylon Robert Armitage Sterndale 1870