1) Abounding in seaweed 2) Evil spirit 3) Kelpie 4) Rife with seaweed 1) Kelpie 
• (n.) An imaginary spirit of the waters, horselike in form, vulgarly believed to warn, by preternatural noises and lights, those who are to be drowned.
[n] - (Scottish folklore) water spirit in the form of a horse that likes to drown its riders