lichening
/ˈlaɪkənɪŋ/
noun
- The process of a surface becoming covered with lichen (a slow-growing plant-like organism that grows on rocks, trees, and walls).
- Scientists are studying the lichening of volcanic rock to understand how life colonizes new land.
- The lichening of the old stone wall gave the garden a very ancient feel.
- The slow lichening of the gravestones made them look like they had been there for centuries.