1. Plant Pathol. a. a decay of seasoned timber, resulting in its becoming brittle and crumbling to a dry powder, caused by various fungi.
b. any of various diseases of plants in which the rotted tissues are dry.
2. any concealed or unsuspected inner decay.
Pronunciation: (drī'rot"),[key] —v.i., v.t.,-rot•ted, -rot•ting. to undergo or cause to undergo the action or effects of dry rot.