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

papain \papa"in\, n. from papaw. physiol. chem.
   a proteolytic ferment, like trypsin, present in the juice of
   the green fruit of the papaw carica papaya of tropical
   america.
   1913 webster
see also:
papaw carica papaya 

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

papaya \papa"ya\, n. prob. from the native name in the west
   indies; cf. sp. papayo papaw, papaya the fruit of the papaw.
   1. bot. a tree carica papaya of tropical america,
      belonging to the order passifloreae; called also
      papaw and pawpaw. it has a soft, spongy stem, eighteen
      or twenty feet high, crowned with a tuft of large,
      long-stalked, palmately lobed leaves. the milky juice of
      the plant is said to have the property of making meat
      tender.
      1913 webster +pjc

   2. the fruit of the papaya tree; it is a dull orange-colored,
      melon-shaped fruit, which is eaten both raw and cooked or
      pickled. the fruit contains papain, a protease.
      1913 webster + pjc
see also:
carica papaya passifloreae papaw pawpaw papain 

[3] : WordNet (r) 2.0

papain
     n : a proteolytic enzyme obtained from the unripe papaya; used
         as a meat tenderizer

Papain >> P Words
Papain, definition of term: Papain
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