* Metaphor: If "war-gear" is used to refer to something that isn't literally gear for war, it could be a metaphor. For example, "He donned his war-gear of sarcasm and wit" uses "war-gear" metaphorically to represent the tools of verbal combat.
* Kennings: "War-gear" could be considered a kenning, a two-word phrase used in Old Norse and Anglo-Saxon poetry to describe a person, place, or thing indirectly. However, this is more likely to be considered a kenning if it's part of a poetic or archaic style.
* Alliteration: The repetition of the "w" sound in "war-gear" could be considered alliteration, a stylistic device used for emphasis or a pleasing sound.
The specific literary device employed depends on the context and the author's intended meaning.