1The branch of science and philosophy concerned with the laws or principles governing the operation of the mind, especially as defined by custom or culture. Formerly also: †a treatise on this (obsolete).
2The science of law; the branch of knowledge concerned with law and justice.
Early 19th century; earliest use found in Thomas Horne (1780–1862), biblical scholar and bibliographer. From nomo- + -logy, after French nomologie.