WordNet sense 1 (something twisted and tight and swollen):

gnarl

WordNet sense 2 (a unit of length used in navigation; equivalent to the distance spanned by one minute of arc in latitude; 1,852 meters):

mi, mile, nautical mile, air mile, international nautical mile, naut mi

WordNet sense 3 (soft lump or unevenness in a yarn; either an imperfection or created by design):

burl, slub

WordNet sense 4 (a sandpiper that breeds in the arctic and winters in the southern hemisphere):

grayback, greyback, Calidris canutus

WordNet sense 5 (tangle or complicate):

ravel, tangle