| 1. | Physical Chemistry. a substance made up of a system of particles with linear dimensions in the range of about 10−7 to 5 × 10−5 cm dispersed in a continuous gaseous, liquid, or solid medium whose properties depend on the large specific surface area. The particles can be large molecules like proteins, or solid, liquid, or gaseous aggregates and they remain dispersed indefinitely. Compare aerosol, emulsion, gel, sol 4 , suspension. |
| 2. | Medicine/Medical. a colloidal substance in the body, as a stored secretion or a cyst. |
| 3. | Physical Chemistry. colloidal. |
A substance made up of particles that are larger than most molecules; these particles do not actually dissolve in substances but stay suspended in them.
Note: Fog, paints, and foam rubber are colloids.
colloid col·loid (kŏl'oid')
n.
A suspension of finely divided particles in a continuous medium from which the particles do not settle out rapidly and are not readily filtered.
The particulate matter so suspended.
The gelatinous stored secretion of the thyroid gland, consisting mainly of thyroglobulin.
Gelatinous material resulting from colloid degeneration in diseased tissue. Also called colloidin.
| colloid (kŏl'oid') Pronunciation Key
A mixture in which very small particles of one substance are distributed evenly throughout another substance. The particles are generally larger than those in a solution, and smaller than those in a suspension. Paints, milk, and fog are colloids. Compare solution, suspension. |