Derogation

[L. derogatio: cf. F. dérogation.]

1. The act of derogating, partly repealing, or lessening in value; disparagement; detraction; depreciation; -- followed by of, from, or to.

I hope it is no derogation to the Christian religion.

He counted it no derogation of his manhood to be seen to weep.

2. (Stock Exch.) An alteration of, or subtraction from, a contract for a sale of stocks.

noun

The act or an instance of belittling: belittlement, denigration, deprecation, depreciation, detraction, disparagement, minimization. See attack/defend, show/hide.

The partial repeal of a law, usually by a subsequent act that in some way diminishes its original intent or scope.

Derogation is distinguishable from abrogation, which is the total annulment of a law.

The noun has 2 meanings:

Meaning #1: a communication that belittles somebody or something
  Synonyms: disparagement, depreciation

Meaning #2: (law) the partial taking away of the effectiveness of a law; a partial repeal or abolition of a law