20 down
River
pilots
brief
crew
from
the
centre
(5)
River pilots brief crew from the centre (5)
hints
0
checks
0
hints
The definition is at the beginning of the clue.
How the clue works
Look at River at the start, that's your definition. Then "from the centre" tells you to dig out the middle letters of each of the next three words: LO from "pilots", I from "brief" and RE from "crew". String those together in order and you've got your river.