They hold liquid war vehicles (5)

I believe the answer is:

tanks

I'm a little stuck... Click here to teach me more about this clue!

'vehicles' is the definition.
(tank is a kind of vehicle)

I cannot understand how the remainder of the clue works.

(Other definitions for tanks that I've seen before include "Armored military vehicles" , "Reservoirs - military vehicles" , "Bombs" , "Armed vehicles" , "Armoured military vehicles" .)

I've seen this clue in the Sydney Morning Herald.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.