fulvic acid

/F UH1 L V IH0 K AE0 S AH0 D/
noun
  1. 1

    A straw-coloured extract of humus that remains after humic acid has been precipitated with acid

  2. 2

    (organic chemistry) The carboxylic acid derivative of cyclopentadiene 5-methylenecyclopenta-1,3-diene-1-carboxylic acid