gnarl

noun

A hard, twisted protuberance or knot on a tree trunk or branch.

"The ancient oak displayed a prominent gnarl."

verb

To twist, contort, or make something knotty and rugged, often due to age.

"Age and weather gnarl the tree's branches."

Thesaurus

Synonyms: murmur, croak, mutter, grumble, knot