1. affected by or relating to canker; having canker sores or lesions
Usage: medical/botanical
2. morally corrupt, malicious, or destructive; tending to cause harm or decay
Usage: figurative

Examples

• The cankerous sores in his mouth made eating painful.
• The tree's cankerous branches had to be pruned away.
• His cankerous influence spread negativity throughout the group.
• The cankerous rot had weakened the wooden beam.
• She warned that gossip was a cankerous habit that destroyed friendships.
• The cankerous lesions on the plant indicated a serious infection.