1. The taking in, incorporation, or reception of gases, liquids, light, or heat. Cf. adsorption.

2. In radiology, the uptake of energy from radiation by the tissue or medium through which it passes. See: half-value layer.

3. In radiation or medical physics, the number of disintegrations per second of a radionuclide. Radioactivity. Unit (SI): becquerel.


[L. absorptio, fr. absorbeo, to swallow]

cutaneous absorption

disjunctive absorption

electron resonance absorption

external absorption

interstitial absorption

parenteral absorption

pathologic absorption

percutaneous absorption

photoelectric absorption