fossette

from The Century Dictionary.

• noun A little hollow; a dimple.
• noun In pathology, a small ulcer of the transparent cornea, the center of which is deep.
• noun A hollow of considerable depth in the grinding-face of a tooth, more or less completely surrounded by enamel folds: typically shown in such a tooth as the molar of a rhinoceros. See cut under tooth.

from the GNU version of the Collaborative International Dictionary of English.

• noun A little hollow; hence, a dimple.
• noun (Med.) A small, deep-centered ulcer of the transparent cornea.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun A little hollow; a dimple.
• noun medicine A small, deep-centred ulcer of the transparent cornea.
• noun dentistry A small depression in the crown of a tooth