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

tannin \tan"nin\, n. cf. f. tannin. chem.
   same as tannic acid, under tannic.
   1913 webster
see also:
tannic acid tannic 

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

tannic \tan"nic\, a.
   of or pertaining to tan; derived from, or resembling, tan;
   as, tannic acid.
   1913 webster

   tannic acid. chem.
   a an acid obtained from nutgalls as a yellow amorphous
       substance, c14h10o9, having an astringent taste, and
       forming with ferric salts a bluish-black compound, which
       is the basis of common ink. called also tannin, and
       gallotannic acid.
   b by extension, any one of a series of astringent
       substances resembling tannin proper, widely diffused
       through the vegetable kingdom, as in oak bark, willow,
       catechu, tea, coffee, etc.
       1913 webster
see also:
tannic acid c14h10o9 tannin gallotannic acid 

[3] : WordNet (r) 2.0

tannin
     n : any of various complex phenolic substances of plant origin;
         used in tanning and in medicine syn: tannic acid
see also:
tannic acid 

Tannin >> T Words
Tannin, definition of term: Tannin
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