Correlation /(-l?"sh?n)/

Cor·re·la·tion

Correlation

n.
  1. Reciprocal relation; corresponding similarity or parallelism of relation or law; capacity of being converted into, or of giving place to, one another, under certain conditions; as, the correlation of forces, or of zymotic diseases.

Phrases & Compounds
Correlation of energy
the relation to one another of different forms of energy; -- usually having some reference to the principle of conservation of energy. See Conservation of energy, under Conservation.
Correlation of forces
the relation between the forces which matter, endowed with various forms of energy, may exert.