mod·i·fy 
(mŏdə-fī′)
(mŏdə-fī′)v. mod·i·fied, mod·i·fy·ing, mod·i·fies
v.tr.
1. To change in form or character; alter.
2. To make less extreme, severe, or strong: refused to modify her stand on the issue.
3. Grammar To qualify or limit the meaning of. For example, summer modifies day in the phrase a summer day.
4. Linguistics To change (a vowel) by umlaut.
v.intr.
To be or become modified; change.
[Middle English modifien, from Old French modifier, from Latin modificāre, to measure, limit : modus, measure; see med- in the Appendix of Indo-European roots + -ficāre, -fy.]
mod′i·fi′a·bili·ty n.
modi·fi′a·ble adj.