Ne`re*o*cys"tis (?), n. [NL. See Nereid, and Cyst.] Bot.
A genus of gigantic seaweeds.
⇒ Nereocystis Lutkeana, of the North Pacific, has a stem many fathoms long, terminating in a great vesicle, which is crowned with a tuft of long leaves. The stem is used by the Alaskans for fishing lines.
© Webster 1913.