1 word for AAACDDGGIIINNNORSSSTT 16-letter words

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16 letters (1)

Slit in the back of a jacket
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V
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T
Hint 1 meaning
The anal opening of certain invertebrates and fishes; also, the external cloacal opening of reptiles, birds, amphibians, and many fishes.
Hint 2 anagram
TNEV
Hint 3 another clue
Discharge
3 +1