gnarl (EN)
verb, noun

verb “gnarl”

gnarl; he gnarls; past gnarled, part. gnarled; ger. gnarling
  1. to twist or make something knotted
    The old tree's roots gnarled around the rocks.

noun “gnarl”

sg. gnarl, pl. gnarls
  1. a hard, twisted bump on a tree
    The old oak tree had a large gnarl on its trunk where the branches twisted together.