de·te·ri·o·rate 
(dĭ-tîrē-ə-rāt′)
(dĭ-tîrē-ə-rāt′)v. de·te·ri·o·rat·ed, de·te·ri·o·rat·ing, de·te·ri·o·rates
v.tr.
To diminish or impair in quality, character, or value: Time and neglect had deteriorated the property.
v.intr.
1. To grow worse; degenerate: The weather deteriorated overnight.
2. To weaken or disintegrate; decay: The nation's highways are deteriorating at a rapid pace.
[Late Latin dēteriōrāre, dēteriōrāt-, from Latin dēterior, worse; see de- in the Appendix of Indo-European roots.]
de·te′ri·o·ration n.
de·teri·o·ra′tive adj.