blister canker

noun

: a disease of the apple tree caused by an ascomycetous fungus (Nummularia discreta) producing roughened and blackened cankers on the trunk and larger limbs

called also apple pox

The Ultimate Dictionary Awaits

Expand your vocabulary and dive deeper into language with Merriam-Webster Unabridged.

1. Expanded definitions
2. Detailed etymologies
3. Advanced search tools
4. All ad-free

Discover what makes Merriam-Webster Unabridged the essential choice for true word lovers.

Start Your Free Trial Now