21 down
1
brief
period
gripping
nation
(8)
1 brief period gripping nation (8)
hints
0
checks
0
hints
The definition is at the beginning of the clue.
How the clue works
The 1 is a cross-reference to another clue whose answer defines these fish. PHAS (PHASE = 'period' shortened or 'brief') grips IRAN ('nation') to give P(IRAN)HAS = PIRANHAS.