نكاث doesn't appear in Hans Wehr's Modern Standard Arabic dictionary, but Lane's Arabic-English Lexicon has 2 entries for it, distinguished by diacritics. Select one below for the full classical Arabic definition.

• نُكَاثٌ

  نُكَاثٌ ذ Pustules which come forth in the mouths of camels: (K:) as also لُكَاثٌ. (TA.) -b2- A disease in the نَكَفَتَانِ of a camel, which are two prominent bones by the fat parts of the two ears: it is also called نُك…

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• نَكَّاثٌ

  نَكَّاثٌ ذ One who undoes, or untwists, thread, and twists it again, or, to twist it again. (TA.) [See نِكْثٌ.] -b2- نَكَّاثٌ لِلْعَهْدِ (tropical:) One who is wont to dissolve, violate, or break, his covenant, or compac…

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