[1] : The Collaborative International Dictionary of English v.0.48

vinegar \vin"egar\, 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 zool., 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
see also:
wine eager aromatic vinegar mother of vinegar mother radical vinegar 
thieves' vinegar thief vinegar eel leptodera oxophila anguillula acetiglutinis 
vinegar worm vinegar lamp vinegar plant vinegar tree rhus typhina 
wood vinegar wood 

[2] : The Collaborative International Dictionary of English v.0.48

eel \eel\, n. as. ?l; akin to d., g.,  dan. aal, icel. =all,
   sw. al. zo"ol.
   an elongated fish of many genera and species. the common eels
   of europe and america belong to the genus anguilla. the
   electrical eel is a species of gymnotus. the so called
   vinegar eel is a minute nematode worm. see conger eel,
   electric eel, and gymnotus.
   1913 webster
see also:
anguilla gymnotus vinegar eel conger eel electric eel 

[3] : WordNet (r) 2.0

vinegar eel
     n : minute eelworm that feeds on organisms that cause
         fermentation in e.g. vinegar syn: vinegar worm, anguillula
         aceti, turbatrix aceti
see also:
vinegar worm anguillula aceti turbatrix aceti 

Eel >> E Words
Eel, definition of term: Eel
eel_pag1.html

Electric Eel >> E Words
Electric Eel, definition of term: Electric Eel
electric+eel_pag1.html