D defs.my
Entry 2 senses Webster, 1913

defoliation

· de·fo·li·a·tion · IPA /diːˌfəʊliːˈ(j)eɪʃən/
01 n. The separation of ripened leaves from a branch or stem; the falling or shedding of the leaves.
  1. 1.
    The separation of ripened leaves from a branch or stem; the falling or shedding of the leaves.
  2. 2.
    the act or process of causing plants to lose their leaves, especially by application of a chemical agent.