The coming together of a group of afferent nerves upon a motoneuron of the ventral horn of the spinal cord.

Independent development of similarities between unrelated cultures.

A condition in which the electron beams of a multibeam cathode-ray tube intersect at a specified point, such as at an opening in the shadow mask of a three-gun color television picture tube; both static convergence and dynamic convergence are required.

Development of similarities between animals or plants of different groups resulting from adaptation to similar habitats.

Diminution of the interval between geologic horizons.

The line of demarcation between turbid river water and clear lake water.

The property of having a limit for infinite series, sequences, products, and so on.

The increase in wind setup observed beyond that which would take place in an equivalent rectangular basin of uniform depth, caused by changes in platform or depth.

A condition in the ocean in which currents or water masses having different densities, temperatures, or salinities meet; results in the sinking of the colder or more saline water.

The intersection of light beams or particles within a small region, or the narrowing of a single beam so that it passes through a small region.