The most common and most likely answer to this crossword clue is the 6 letter word TIGRIS
T
I
G
R
I
S
More clues leading to the result TIGRIS
- Losing energy, predator is in waterway
- Strange grit is found in river
- Asian runner, fierce cruel person, is losing energy
- Flower arrangement’s last bloom, good for bedding
- Oddly, thing drains a lot of water
- 8 is under grit spreader
- Form of address bastard used in return
- Terminating in Gulf, river irrigating Sumer, primarily?
- In Serengeti, grisly river!
- Oddly thin, grey flower
Buddy explains!

The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.