modify

American Heritage® Dictionary of the English Language, Fourth Edition

1. v. To change in form or character; alter.
2. v. To make less extreme, severe, or strong: refused to modify her stand on the issue.
3. v. Grammar To qualify or limit the meaning of. For example, summer modifies day in the phrase a summer day.
4. v. Linguistics To change (a vowel) by umlaut.
5. v. To be or become modified; change.

Century Dictionary and Cyclopedia

1. To qualify; especially, to moderate or reduce in extent or degree.
2. To change the properties, form, or function of; give a new form to; alter slightly or not very much; vary: as, to modify the terms of a contract; a prefix modifies the sense of a word; light is modified by its transmission through certain media. In crystallography one crystalline form is said to modify another when the two occur together in the same crystal, the modified form predominating; thus, the cube may be modified by the trapezohedron. A highly modified crystal is one showing a large number of different crystalline forms.

Wiktionary

1. v. transitive To make partial changes to.
2. v. intransitive To be or become modified.

GNU Webster's 1913

1. v. To change somewhat the form or qualities of; to change a part of something while leaving most parts unchanged; to alter somewhat
2. v. To limit or reduce in extent or degree; to moderate; to qualify; to lower.

WordNet 3.0

1. v. add a modifier to a constituent
2. v. make less severe or harsh or extreme
3. v. cause to change; make different; cause a transformation