1) Bent 2) Cantankerous 3) Covered with knobs or knots 4) Crabby 5) Crooked 6) Exclusively Saxon word 7) Exclusively Anglo word 8) Gnarly 9) Knobbed 10) Knobby 11) Knotted 12) Knotted up 13) Knotty 14) Knotty and twisted 15) Like an old oak tree 16) Like an old tree trunk 17) Like windblown trees 18) Made knotty 1) Crooked 2) Gnarly 3) Knobbed 4) Knotted 5) Knotty 6) Knurled 7) Knurly 8) Worn 
• (imp. & p. p.) of Gnarl • (a.) Knotty; full of knots or gnarls; twisted; crossgrained.
Gnarled adjective Knotty; full of knots or gnarls; twisted; crossgrained. « The unwedgeable and gnarléd oak.» Shak. 
[adj] - used of old persons or old trees
gnarly adjective used of old persons or old trees; covered with knobs or knots; `gnarled and knotted hands`; `a knobbed stick`
(of trees) full of or covered with gnarls; bent; twisted. · having a rugged, weather-beaten appearance: a gnarled old sea captain. · crabby; cantankerous.