Common words:
* war
* warm
* warn
* warrant
* warrior
* warfare
* warpaint
Less common words:
* warble
* wardrobe
* warehouse
* warlock
* warpath
* warship
* wart
* wary
* wash
* washout
* wasp
* waste
* watch
* water
Words with "war" as a root or prefix:
* prewar
* postwar
* antiwar
* warring
Let me know if you'd like to explore any of these words in more detail!