Martial - derived from Mars, the god of war. If it isn't about war, it isn't, strictly speaking, martial.
While we are quibbling semantics, in fact, Mars was the god of offensive war. Mars was originally a god of the border between cultivated and wild lands. For the Romans, Pax Romana could only be established when the wild was tamed and cultivated (this, by the way, has been the excuse for genocide forever. See: Kiernan, Ben, Blood and Soil: A World History of Genocide and Extermination from Sparta to Darfur, Yale University Pres, New Haven, Connecticut, 2007). At any rate, the Romans merged this trivial "god of the margins" with the Greek Ares, and hence Mars became the Roman god of extending the borders into the wilds.
Donn did not have much of a sense of humor regarding his pet theories (newly made shibboleths). So pointing this out to him, I suggested that he needed to fine-tune things further, because Minerva (the Roman Athena) was, in fact, the protector of cities, the goddess of defensive warfare. I pointed out that Maniwa Nen-ryu defined itself as purely defensive, a protector of their own land and that even their combative theories were based almost solely on go-no-sen, eliciting attacks which they then crushed. I therefore suggested that he should examine martial schools a little more closely and perhaps divide them in primarily Martial as opposed to primarily Minervic. He was not amused (which amused me more).
While I accept that the term martial is derived from Mars the god of (offensive) war and therefore if the art is not strictly speaking to be applied in war then it's not martial; however in the context of Japan this makes all "martial arts" technically anachronistic due to the fact that the Samurai class no longer exists. I acknowledge that what I do is very detached from what the Samurai did in Feudal Japan because I am not a soldier and I do not do martial arts professionally for use in the field of combat. However, gendai arts in Japan are designed to preserve the Samurai heritage and even though they are open to the public they are a way of keeping ancient martial techniques alive. Art forms that have been developed over centuries deserve to be preserved for posterity. We may be speaking of semantics here but meanings of words do change over time. Language is organic.
I actually like the idea of dividing martial arts into martial and minervic forms; I would be prepared to accept that Aikido falls into the latter; it is an art form after all that is primarily defensive
in both its techniques and philosophy. In many ways its very helpful, especially in the case of Aikido in which O'Sensei's vision of the true meaning of Budo was a radical departure from the traditional understanding of the term.