1. (Science: cell biology) The adjustment of an organism to its environment or the process by which it enhances such fitness.
2. (Science: ophthalmology) The normal ability of the eye to adjust itself to variations in the intensity of light, the adjustment to such variations.
3. (Science: neurology, physiology) The decline in the frequency of firing of a neuron, particularly of a receptor, under conditions of constant stimulation.
4. (Science: 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. (Science: microbiology) The adjustment of bacterial physiology to a new environment.
Origin: L. Adaptare = to fit