dieback

[dahy-bak]
noun Plant Pathology.
  1. a condition in a plant in which the branches or shoots die from the tip inward, caused by any of several bacteria, fungi, or viruses or by certain environmental conditions.

Origin of dieback

An Americanism dating back to 1885–90; die1 + back2
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

British Dictionary definitions for dieback

dieback

noun
  1. a disease of trees and shrubs characterized by death of the young shoots, which spreads to the larger branches: caused by injury to the roots or attack by bacteria or fungi
  2. any similar condition of herbaceous plants
verb die back
  1. (intr, adverb) (of plants) to suffer from dieback
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012