1. <cell biology> The adjustment of an organism to its environment or the process by which it enhances such fitness.

2. <ophthalmology> The normal ability of the eye to adjust itself to variations in the intensity of light, the adjustment to such variations.

3. <neurology, physiology> The decline in the frequency of firing of a neurone, particularly of a receptor, under conditions of constant stimulation.

4. <dentistry> (a) the proper fitting of a denture, (b) the degree of proximity and interlocking of restorative material to a tooth preparation, (c) the exact adjustment of bands to teeth.

5. <microbiology> The adjustment of bacterial physiology to a new environment.

Origin: L. Adaptare = to fit

(18 Nov 1997)