de·fo·li·ate 
(dē-fōlē-āt′)
(dē-fōlē-āt′)v. de·fo·li·at·ed, de·fo·li·at·ing, de·fo·li·ates
v.tr.
1. To deprive (a plant or a vegetated area, for example) of leaves.
2. To cause the leaves of (a plant or plants) to fall off, especially by the use of chemicals.
v.intr.
To lose foliage.
[Late Latin dēfoliāre, dēfoliāt- : Latin dē-, de- + Latin folium, leaf; see bhel-3 in the Appendix of Indo-European roots.]
de·foli·ate (-ĭt) adj.
de·fo′li·ation n.
de·foli·a′tor n.