[syn: bitterness, acrimony, acerbity, jaundice, tartness, thorniness]
The Collaborative International Dictionary of English v.0.48:
Tartness \Tart"ness\, n.
   The quality or state of being tart.
   [1913 Webster]
   Syn: Acrimony; sourness; keenness; poignancy; severity;
        asperity; acerbity; harshness. See Acrimony.
        [1913 Webster]
WordNet (r) 3.0 (2006):
tartness
    n 1: the taste experience when vinegar or lemon juice is taken
         into the mouth [syn: sour, sourness, tartness]
    2: a sharp sour taste [syn: acerbity, tartness]
    3: a rough and bitter manner [syn: bitterness, acrimony,
       acerbity, jaundice, tartness, thorniness]