nVarecThe calcined ashes of any coarse seaweed used for the manufacture of soda and iodine; also, the seaweed itself; fucus; wrack.
Century Dictionary and Cyclopedia
nvarecIn the original Freuch use of this word it applies to the seaweed itself before burning, but it is now commonly applied to the ash which results from the burning, utilized for the extraction from it of iodine and salts of potassium, as formerly of sodium carbonate. Also vareck.
nvarecAn impure sodium carbonate made in Brittany: it corresponds to the English kelp. Brande and Cox.
Chambers's Twentieth Century Dictionary
nVarecvar′ek a Breton impure sodium carbonate.
Webster's Revised Unabridged Dictionary
F. varech,; of Teutonic origin. See Wrack seaweed, wreck