Definition of "tangled"

Troubled, 'wilder'd, and forlorn, / Dark, benighted, travel-worn, / Over many a tangled spray, / All heart-broke I heard her say

1789, William Blake, “A Dream”, in Songs of Innocence

That like a mighty river onward streams / In multitudinous channels ruthlessly, / Past tangled isles and barriers of sand

1919, Henry Head, “Paris. April, 1916”, in Destroyers and Other Verses