tangle (v.)

mid-14c., tanglen, "encumber, enmesh, knit together confusedly," a shortening of entangle in some cases, in others probably a nasalized variant of tagilen "to involve in a difficult situation, entangle," from a Scandinavian source (compare dialectal Swedish taggla "to disorder," Old Norse þongull "seaweed"), from Proto-Germanic *thangul- (source also of Frisian tung, Dutch tang, German Tang "seaweed").

If so, the original sense might be "seaweed" as something that entangles (itself, or oars, or fishes, or nets). "The development of such a verb from a noun of limited use like tangle 1 is somewhat remarkable, and needs confirmation" [Century Dictionary].

The transitive sense of "bring others into one's power, entrap" is from mid-15c. In reference to material things, from c. 1500. The meaning "fight with" is American English, recorded by 1928. Related: Tangled; tangling. Tanglefoot (1859) was Western U.S. slang for "strong whiskey." Tanglesome "complicated" is attested from 1823.

1610s, "a tangled condition, a snarl of threads," from tangle (v.). The older word meaning "large type of seaweed" (Middle English) is from Old Norse; also

"tall, lank person."