Source : Webster's Revised Unabridged Dictionary (1913)

Modification \Mod`i*fi*ca"tion\, n. [L. modificatio a measuring:
   cf. F. modification. See {Modify}.]
   The act of modifying, or the state of being modified; a
   modified form or condition; state as modified; a change; as,
   the modification of an opinion, or of a machine; the various
   modifications of light. --Bentley.

Source : WordNet®

modification
     n 1: the act of making something different (as e.g. the size of a
          garment) [syn: {alteration}, {adjustment}]
     2: slightly modified copy; not an exact copy; "a modification
        of last year's model"
     3: the grammatical relation that exists when a word qualifies
        the meaning of the phrase [syn: {qualifying}, {limiting}]
     4: an event that occurs when something passes from one state or
        phase to another; "the change was intended to increase
        sales"; "this storm is certainly a change for the worse";
        "the neighborhood had undergone few modifications since
        his last visit years ago" [syn: {change}, {alteration}]