Definition of leveling:
(n) :
The process of making something level.
(n) :
(surveying, archaeology) The process of measuring levels to establish heights and altitudes.
(n) :
(linguistics) Ellipsis of paradigm leveling, the replacement of irregular forms by regular forms. [(linguistics, linguistic morphology) Regularisation of a paradigm, alignment of irregular forms on regular forms; replacement of irregular forms by regular forms in an inflection.]