Wood vinegar

Vinegar Vin"e*gar, n. [OE. vinegre, F. vinaigre; vin wine (L. vinum) + aigre sour. See {Wine}, and {Eager}, a.] 1. A sour liquid used as a condiment, or as a preservative, and obtained by the spontaneous (acetous) fermentation, or by the artificial oxidation, of wine, cider, beer, or the like. [1913 Webster]

Note: The characteristic sourness of vinegar is due to acetic acid, of which it contains from three to five per cent. Wine vinegar contains also tartaric acid, citric acid, etc. [1913 Webster]

2. Hence, anything sour; -- used also metaphorically. [1913 Webster]

Here's the challenge: . . . I warrant there's vinegar and pepper in't. --Shak. [1913 Webster]

{Aromatic vinegar}, strong acetic acid highly flavored with aromatic substances.

{Mother of vinegar}. See 4th {Mother}.

{Radical vinegar}, acetic acid.

{Thieves' vinegar}. See under {Thief}.

{Vinegar eel} (Zo["o]l.), a minute nematode worm ({Leptodera oxophila}, or {Anguillula acetiglutinis}), commonly found in great numbers in vinegar, sour paste, and other fermenting vegetable substances; -- called also {vinegar worm}.

{Vinegar lamp} (Chem.), a fanciful name of an apparatus designed to oxidize alcohol to acetic acid by means of platinum.

{Vinegar plant}. See 4th {Mother}.

{Vinegar tree} (Bot.), the stag-horn sumac ({Rhus typhina}), whose acid berries have been used to intensify the sourness of vinegar.

{Wood vinegar}. See under {Wood}. [1913 Webster]