May be of love or war (3)

I believe the answer is:

tug

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

'war' is the definition.
(thesaurus)

I cannot understand how the remainder of the clue works.

(Other definitions for tug that I've seen before include "Small boat for pulling others" , "Pull vigorously at or tow" , "Pull like small boat" , "Haul" , "Pull at the towing vessel" .)

I've seen this clue in the Evening Standard.

Want a hint initially instead of a full solution? Install my app